adec mathematics curriculum 2011 cnpm 3 objectives ... · counting, partitioning and calculating a1...

Counting, partitioning and calculating

A1

60

2 weeks

Unit overviewChildren read, write and partition two-digit and three-digit numbers, and position them on a number line. They useordinal numbers in real-life and practical situations.

They count forwards and backwards from zero and then from any number in steps of constant size (1, 2, 3, 4, 10 and100). They predict whether a given number will appear in a sequence and solve problems involving sequences.

Children identify and use links between counting in 2s and 4s, counting in 3s and 6s, and counting in 5s and 10s.They use grouping to count larger sets of objects.

They compare and order numbers up to 1000, using the appropriate symbols and vocabulary including < and >.

Children recall all the addition and subtraction facts for each number to 20. They carry out the addition and subtractionof multiples of 10 by using known number facts. They use mental strategies, including bridging through a multiple of 10,to add or subtract one-digit numbers to or from two-digit numbers.

They identify and place multiples of 10 or 100 on a number line and then use their knowledge of place value to positionother numbers.

Children solve number puzzles involving calculations. They record their answers systematically, using lists or tables whereappropriate. They explain how they worked out their answers and how they know that they found all the possiblesolutions, discussing and comparing strategies and answers with other children.

ADEC Mathematics Curriculum 2011 CNPM 3Grade 3 Unit A1 | 2 weeks | Counting, partitioning and calculating

Objectives Objectives Lesson(s)

Strand: Using and applying mathematics

• Describe and explain methods, choices and solutions 2, 4to puzzles and problems, orally and in writing, using pictures and diagrams

Strand: Number Strand: Counting and understanding numberSub–Strand: Whole number

Read, write, order and represent two-digit numbers • Read, write and order whole numbers to at least 1000 1 – 5and three-digit numbers and position them on a number line; count on from • read, order and represent three-digit numbers to and back to zero in single-digit steps or multiples of 10

at least 999 and recognise the place value of the digits• count forwards or backwards by ones, twos, fives and • Partition three-digit numbers into multiples of 100, 5

tens from a three-digit number 10 and 1 in different ways

Strand: Number Strand: Knowing and using number factsSub–Strand: Addition and subtraction

Use a range of mental strategies and recording • Derive and recall all addition and subtraction facts 6 – 8methods for addition and subtraction involving at least for each number to 20, sums and differences of two-digit numbers multiples of 10 and number pairs that total 100• recall number facts to at least 20• develop a range of mental strategies and informal Strand: Calculating

recording methods for addition and subtraction involving one-digit numbers and two-digit numbers • Add or subtract mentally combinations of one-digit 9 – 10

and two-digit numbers

Note: UK Primary Framework for Mathematics (2006) End-of-year expectations (key objectives) in bold.

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A1 Counting, partitioning and calculating

Children’s targets• Explain how I solve problems

• Count on and back in single-digit steps

• Read and write numbers to 1000 and put them in order

• Split a number into 100s, 10s and 1s

• Explain how the digits in a number change when I countin 10s or 100s

• Know the sum and difference of any pair of numbersto 20

• Add and subtract multiples of 10 in my head

• Know pairs of multpiles of 10 that total 100

• Add and subtract one-digit and two-digit numbers inmy head (e.g. 62 + 7, 7 + 45, 48 – 6, 60 – 8)

Prior learningBuild on previous learning by checking children can:

• give oral explanations of the methods they used tosolve single-step problems, recognising and writing thecalculations involved

• work with numbers to 100, reading, writing, partitioningand ordering them

• say or write all addition and subtraction facts for allnumbers to 10, all number pairs totalling 20 or less, andall number pairs of multiples of 10 totalling 100 or less

• carry out mentally additions and subtractions involvingone-digit numbers

Key aspects of learning• Problem solving

• Reasoning

• Social skills

• Communication

Vocabularyproblem, solution, calculate, calculation, answer, method,explain, reasoning, pattern, predict

place value, partition, digit, units, ones, tens, hundreds,one-digit number, two-digit number, three-digit number,compare, order, equals (=), less than (<), greater than (>)

count on/back, add, subtract, group, sum, total,difference, plus, minus

Speaking and listeningExplain a process or present information, ensuring itemsare clearly sequenced, relevant details are included andaccounts ended effectively.

Cross-curricular links ScienceLight and shadows: Measure and put in order lengths ofshadows at different times of the day. Calculatedifferences between them.

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Whole numbers to 1000

Main teaching

• Begin by counting on and back in steps of 1 to 10, in steps of 10 to 100 andin steps of 100 to 1000.

• Display the number 235. Ask: Who can read this number? Which of thedigits has the greatest value? How many hundreds are in this number?How many tens? How many units? Reveal their place values. Explain to thechildren how the number is made up of the sum of multiples of 100, 10 and 1,i.e. 235 = 200 + 30 + 5.

• Ask: How would you write this number in words?

• Repeat for the other three-digit numbers 426, 634, 795.

• Display 490. Ask: Who can read this number? How many tens are there?Hide the 0 and show 49. Ask: How many tens are there now? Reveal 490and say: Zero is a place holder. It shows that there are no units in thenumber 490. Ask the children to make 490 with their place value cards.Ask: Who can explain why they did not use a units card?

• Display 409. Ask the children to make the number with their place value cards.Ask: Which cards did you use? Why did you not need a tens card?

• Display 490 and 409. Ask: How are these numbers the same? How are they different? How can you tell which is the larger number?Which digit must you look at?

• Repeat with similar pairs of three-digit numbers containing a zero.

Oral and mental starterChoose an activity from Strand 2

Vocabulary place value; digit; ones; tens; hundreds; one-digit number; two-digit number; three-digit number;

compare; order

Objective • Read and write whole numbers to at least 1000; count on from and back to zero in single-digit steps ormultiples of 10s

SoftwareTeach A1 L1

Resources place value cards (per child)

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5

6

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Unit A1

1Lesson

63

• Draw an empty number line and on it mark the numbers 357, 750, 573 and 537.What clues do you use to find the smallest / largest number?

• Write a 3-digit number with a zero in the tens place and read it to me.

Plenary• Display the numbers 99, 700, 126, 717, 824, 404, 133, 209, 660, 909 and 130.

• Point to several numbers in turn and ask: Who can read this number? How manyhundreds / tens / units does it have?

• Ask: Which numbers have no tens? … no units? If you count in tens from 99, which ofthese numbers will you reach? Why does the units digit not change?

• Conclude the lesson by counting on and back in steps of 1 to 10, in steps of 10 to 100 andin steps of 100 to 1000.

Common difficulties and remediationA common error is recording numbers such as three hundred and four as 3004. Use place value cards toshow how a zero is hidden when the units card is placed in position..

Pupil activitiesPupil Book 3AMobile numbers

7

Differentiation PackSpell check

SCM 1

Resources place value cards: 200, 500, 30, 60, 4 and 9

What to do Children find all the different 3-digit numbersthey can make with the above place valuecards. They then write the numbers in order,smallest to largest.

Additional Activity

A1 Counting, partitioningand calculating

L1

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Cardinal and ordinal numbers

Main teaching

• Gather the children in an appropriate space, distribute the cards and ask thechildren to hold their cards in front of them. Say: Find the person holding thenumber that is two more than yours and stand on the left of that person.This will produce two groups, an odd group and an even group.

• Ask the children in the odd numbers group to call out their numbersbeginning with the child holding card 1, e.g. 1, 3, 5, 7, 9, … Repeat for theeven numbers group beginning with card 2, e.g. 2, 4, 6, 8, 10, ... Encouragechildren to see that each group is counting in steps of 2 and that their cardsform the sequences of odd and even numbers.

• Refer to the odd group and say: 1 is the first odd number. 3 is the secondodd number and 5 is the third odd number. Ask: Who has the 4th / 5thodd number?

• Ask the children in the odd group to hide their cards. Ask the even group:What number will the 6th / 8th / 10th person in the odd group beholding? The children display the cards 11 / 15 / 19.

• Repeat the activity for the even group.

• Display the even numbers and position diagram. Ask: What is the position of12 / 14 in the sequence of even numbers? (6th / 7th) Explain how youworked it out. What pattern did you spot? What is the even number inthe 10th position? (20) Who can predict the position of 100? (50th)

• Display the 2 blue, 1 red pattern strip. Ask: What colour is the 3rd square?(red) What number is the 2nd / 3rd red square? If the pattern went on,what would be the position of the next red square? (12th) How would youdescribe the pattern of red squares? (going up in threes)

• Display the 3 blue, 1 red pattern strip. Ask: What do you count on each timeto make this pattern? (fours) Who can predict the colour of the 16th /18th square? (red / blue) Explain how you worked it out.


Vocabulary explain; reasoning; pattern; predict; place value; digit; compare; order; count on; first, second, third…;

odd; even

Objectives • Describe and explain methods, choices and solutions to puzzles and problems, orally and in writing,using pictures and diagrams

• Read, write and order whole numbers to at least 1000 and position them on a number line

SoftwareTeach A1 L2

Resources 1 to 30 number cards (or more or less depending on the number ofchildren in the class)

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2

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Unit A1

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• What is the 5th even number? The 6th odd number?

• Write the 10th and 20th letters of the alphabet.

• Salem made a row of red and blue counters. If every 4th counter is red, what is thecolour of the 20th counter? What is the position in the row of the 5th blue counter?

Pupil activitiesPupil Book 3A

Fruit card orderingPage 5

Differentiation PackBorder patterns

ECM 1


L2

Common difficulties and remediationRemind children that the order is from left to right.

Resources 4 strips of paper (per child)

Plenary• Review answers to the activity in the Pupil Book and correct any errors.

• Display the 3 blue, 1 red pattern strip and ask: What size of step would you count on sothat every square you landed on was red? If the pattern continued, what would be thecolour of the 40th square? The 100th square?

• Referring to the ECM activity, ask: In question 4, what is the colour of the 15thsquare tile?

3

HomeworkHomework PackLunch queue order

HCM 1

66

Grouping in tens

Main teaching

• Display 43 sheep. Say: The shepherd wants to find out how many sheep hehas altogether. If he were to count the sheep one by one it would takehim a long time. Ask: Can anyone suggest a way of counting or groupingthem so that he could find the total more quickly? (group in tens)

• Ask one or two children to come to the front and arrange the sheep intogroups of 10.

• Count in tens with the class to find the total. Say: 10, 20, 30, 40. Count anyremaining sheep to make the total, e.g. 41, 42, 43.

• Repeat with 65 chickens.

• Display 10 tens Dienes rods. Say: How many groups of ten are therealtogether? (10) Ask: How many are 10 tens? Count in tens with the classto 100.

• Ask five children to stand in front of the class. Collect 20 objects. Say: I wouldlike to group these 20 objects so that each child has the same amount.

• Ask: How many groups will I need? (5) Why? (there are 5 children) Howmany will be in each group? (4) How do you know? (a group of 4 five timesequals 20)

• Repeat the above grouping with four children.

• Say: We can group objects in different ways. You must think about themost useful way to group objects or numbers together. Grouping in tensis not always best.


Vocabulary digit; ones; tens; group

Objective • Read and write whole numbers; count on from and back to zero in single-digit steps or multiples of 10

SoftwareTeach A1 L3

Resources 20 objects that can be grouped, e.g. interlocking cubes / straws /counters

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3

1

Unit A1

3Lesson

Children maysuggest grouping in

twos or fives. Commendtheir suggestions butencourage them to findan even quicker method.

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• Dad gets 3 boxes of golf balls on his birthday. There are 12 golf balls in each box.How many golf balls has he altogether?

• The teacher needs 60 new pencils for her class. The pencils are in packets of 10.How many packets does she order?

• Tennis balls are sold in tins of 3. On Saturday the shop sold 9 tins. How many tennisballs were sold altogether?

Plenary• Ask questions such as: How many groups of ten can you make with 80 / 50 / 94 / 27

cubes? What is the best way to group 400 / 450 cubes? Continue with other numbers.

• Ask children to suggest examples of items grouped together and why the items have beengrouped as such, e.g. flowers in bunches of 5 or 10, eggs in boxes of 6 or 12 and so on.

Pupil activitiesPupil Book 3AFind the groups

Page 6


L3

Resources 5 number cards: range 50 to 99 (per pair); 1–6 spinner (per pair); base 10 materials: 10sand 1s (per child)

Resources 5 number cards: range 200 to 300 (per group); 0-9or 0-12 spinner (per group); base 10 materials:100s, 10s and 1s (per child).

What to do In groups, children play the game ‘Hit the target’(see game in the Pupil Book for rules). Theyexchange 10 ones cubes for a 10 rod and 10tens rods for a 100 block to reach thetarget number.

Additional Activity

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Counting in 3s and 4s

Main teaching• Display the 0 to 40 number line. Say: Lets begin at zero and count on in

steps of 3. Say: 0, 3, 6, 9 …

• Display the multiples of 3 sorting diagram.

• Ask: What do you notice about the numbers in the circle? (same as stepsof 3) Say: This is the set of multiples of 3.

• Once again display the 0 to 40 number line and say: Lets begin at zero andcount on in steps of 4. Say: 0, 4, 8, 12 …

• Display the multiples of 4 sorting diagram.

• Ask: What do you notice about the numbers in the circle? (same as stepsof 4) Say: This is the set of multiples of 4.

• Display both sorting diagrams. Ask: Can you find a number that is both amultiple of 3 and a multiple of 4? (12, 24, 36)

• Ask: Can anyone think of a way that we could show that the numbers 12,24 and 36 belong to both sets of multiples? (overlap the 2 circles so that athird set is formed)

• Display the Venn diagram.

• Say: By overlapping the circles, the numbers 12, 24 and 36 are nowcontained in both sets of multiples.

• Ask: How many numbers are multiples of 3? Of 4? What can you sayabout 24? (multiple of 3 and 4) Can you predict the next number after 36that will be a multiple of both 3 and 4? (48)

• Ask: You are counting in steps of 2 from 0. In which circle will you say allof its numbers? (multiples of 4) What if you are counting in steps of 6?


Vocabulary digit; ones; tens; count on; count back; multiple

Objectives • Read, write and order whole numbers to at least 1000 and position them on a number line; count onfrom and back to zero in single-digit steps

• Describe and explain methods, choices and solutions to puzzles and problems, orally and in writing,using pictures and diagrams

SoftwareTeach A1 L4

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Unit A1

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Homework

• What is the smallest number you will get if you keep subtracting 6 from 40?

• What numbers between 30 and 40 are multiples of both 2 and 3?

• What is the multiple of 4 closest to 35?

Plenary• Review the work completed by the children for question 1 in both sections of the Pupil Book.

• Ask: What numbers are multiples of both 3 and 5? (15, 30) Of 4 and 5? (20, 40)

• Ask: Who can predict the number greater than 40 which is a multiple of 3, 4 and 5?

• Ask: What numbers between 20 and 40 are multiples of 2 and 4? (20, 24, 28, 32, 36, 40)Are multiples of 3 and 6? (24, 30, 36) Are multiples of 5 and 10? (20, 30, 40)

Pupil activities

Homework PackFind the multiple

HCM 2

Pupil Book 3ACounting blocks

Page 7

Differentiation PackSunny 3s and 4s

SCM 2

Differentiation PackHare and tortoise game

ECM 2

Resources paper clip (per pair); pencil (per child)

Resources coloured pencils


L4

70

Partitioning 3-digitnumbers

Main teaching

• Display the number 468. Ask: Which of the digits represents the greatestvalue? Split 460 into multiples of 100, 10 and 1. Agree that the 4 in 468represents 400 and thus has the greatest value. Ask the children to make 468with their place value cards.

• On the board write 468 using expanded notation, i.e. 468 = 400 + 60 + 8.

• Display the numbers 375 and 753.

• Ask the children to make each number with their place value cards. Say: Showme the larger / smaller number. Ask: How can you tell which number islarger? Elicit that the hundreds digit tells us this.

• Recall the meaning of the inequalities symbols, < (less than) and > (morethan), and write: 375 < 753.

• Display the numbers 375 and 357.

• Once again ask the children to make the numbers with their place value cards,then ask: What is the same about these two numbers? (same set of digitsand number of hundreds) Which is the larger number? Elicit that we mustnow look at the tens digit.

• Say: If we split each number into hundreds, tens and ones we can seemore clearly which is the larger number.

• On the board write: 375 = 300 + 70 + 5 357 = 300 + 50 + 7

375 > 357

• Repeat for pairs of 3-digit numbers which have zero tens or zero units, e.g. 509, 590 and 270, 207.

• Display the numbers: 648, 804, 950 and 527. Referring to the first number,say: Using your place value cards show me a number that is 200 more /less than 648. Show me a number that is 30 more / less … that is 5 more/ less.

• Repeat for the other 3-digit numbers.


Vocabulary place value; digit; ones; tens; hundreds; one-digit number; two-digit number; three-digit number;

compare; order; equals (=); plus

Objectives • Partition three-digit numbers into multiples of 100, 10 and 1 in different ways• Read, write and order whole numbers to at least 1000

SoftwareTeach A1 L5

Resources place value cards (per child)

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2

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4

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Unit A1

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• Make the number 278 with place value cards. What does the 2 represent? And the 7?Remove the 70 card. What number do you have now?

• What is the largest / smallest number you can make with the digits 2, 5 and 4?

Plenary

• Review answers to questions 1 to 3 in the Pupil Book. Correct any errors in question 3 bypartitioning the numbers.

• Display the numbers: 386, 836, 638, 368, 863 and 683.

• Ask children to work in pairs to write the set of numbers on their paper, in order, smallest tolargest.

• Ask: Who can split 638 / 683 into hundreds, tens and ones?

Common difficulties and remediationChildren may have difficulty in partitioning numbers which have a zero. Use the place value cards to showthe key role of zero as a place holder.

Pupil activitiesPupil Book 3AWinning numbers

Page 8

Resources 6 place value cards, 2 each of: 100s, 10s and 1s (per child)

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L5

Resources paper and pen (per child)

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Addition facts

Main teaching• Begin by asking quickfire questions for addition facts to 10. Ask: What is 3

plus 4? …6 add 2? …8 and two more. Be sure to use a range of appropriatemathematical vocabulary.

• Say: Today, we are going to look at addition facts for numbers from 11 to 20.

• Display the number 15. Write 10 + 5 = 15 underneath. Say: Ten and five canbe added together to equal fifteen. This is one addition fact for fifteen.

• Say: As I know ten and five makes fifteen, I also know that five and tenequals fifteen so I do not need to write this down.

• Ask: Can anyone tell me another addition fact for 15?

• Choose children to answer, record their answers on the board.

• Ask: Are any of the addition facts missing? How could we write them outto make it easier to see?

• Encourage children to work out any missing facts by looking for the pattern,i.e. 15 + 0 = 15, 14 + 1 = 15, 13 + 2 = 15 and so on.

• Read through the addition facts as a class.

• Ask the children to close their eyes, then cover some of the numbers from thecalculations. Replace these with a box e.g. � + 2 = 15, � + 8 = 15,6 + � = 15.

• Point to each box in turn and ask: What number do I need to write in thebox to complete this fact?

• Choose children to answer. Ask: How did you work it out? Write the numberin the box.

• Repeat the above with addition facts for another number from 11 to 20: 13and 16.

• Display all the addition facts for 12. Say: If we know the addition facts for12, we can work out the addition facts for 120.

• Next to 11 + 1 = 12, write 110 + 10 = 120. Ask: What is the same aboutthese two calculations? Establish that some digits are the same, but in thesecond calculation we are adding multiples of ten.


Vocabulary addition; add; sum; total; plus; equals; multiple of ten

Objective • Derive and recall all addition facts for each number to 20, and sums of multiples of 10

SoftwareTeach A1 L6

The additionnumber facts for 15

are all those that have atotal of 15, i.e.

0 + 15

1 + 14

2 + 13

3 + 12

4 + 11

5 + 10

6 + 9

7 + 8

Children should at thisstage understand theconcept (but not thename) of thecommutative law, i.e. 7 + 8 = 8 + 7.

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• Look at this number sentence. What could the two missing numbers be?� + � = 19

• What is 6 + 8? What other additions make 14?

Plenary

• Ask each child to write down 5 numbers from 1 to 18 on their paper.

• Say: I am going to spin these two spinners and call out the numbers. Add themtogether and if you have the answer as one of your numbers you can cross it out.

• Continue spinning the spinners until someone has crossed out all their numbers.


Addition facts bookPage 9

Differentiation PackFlower facts

SCM 3


L6

• Complete the facts for 120 with the class.

• Again, ask the children to close their eyes as you cover some of the numbers.

• Repeat as above.

Main teachingcontinued

Resources coloured pencils (per child)

Resources 2 × 0-9 spinners; paper and pen (per child)

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Subtraction facts

Main teaching

• Begin by asking quickfire questions for subtraction facts to 10. Ask: What is 9minus 4? What is 7 subtract 3? What is the difference between 8 and 5?Be sure to use a range of appropriate mathematical vocabulary.

• Explain the difference between knowing subtraction facts and working themout. Say: 10 subtract 5 is 5. I know this; I do not have to work the answerout. I know it instantly. For 17 minus 8, I do not know the answer straightaway. I need to work it out. 17 subtract 7 is 10, 10 subtract one more is9, so 17 minus 8 equals 9.

• Ask: Who can tell me a subtraction fact that they know the answer to?Ask the rest of the class if they also know that fact. If the majority of the classdo, record the fact on the board, e.g. 20 – 10 = 10, 19 – 1 = 18.

• Invite other children to say calculations that they know. Record on the boardthe facts that most of the class know.

• Display 14 – � = �. Say: Who can tell me a subtraction fact for 14? Recordthe fact on the board. Continue until all the facts have been recorded.

• Ask: How could we write the facts out in a more organised way? Writethem out together, 14 – 0 = 14, 14 – 1 = 13, 14 – 2 = 12 …

• Write 16 on the board. Ask children to work in pairs and write the subtractionfacts for 16 on their paper.

• Display the subtraction facts for 16 and ask children to check they havethem all.

• Say: If we know the subtraction facts for 16, we can work out thesubtraction facts for 160.

• Point to one of the facts for 16. Ask: What subtraction using multiples of tencan this help me work out?

• Record the calculation on the board.

• Repeat for other facts.


Vocabulary subtraction; subtract; minus; take away; difference between; multiple of ten

Objective • Derive and recall all subtraction facts for each number to 20, and differences ofmultiples of 10

SoftwareTeach A1 L7

The subtractionnumber facts for 14

are all those where thefirst number (theminuend) is 14, i.e.

14 – 0 = 14

14 – 1 = 13

14 – 2 = 12

14 – 3 = 11

14 – 4 = 10

14 – 5 = 9

14 – 6 = 8

14 – 7 = 7

14 – 8 = 6

14 – 9 = 5

14 – 10 = 4

14 – 11 = 3

14 – 12 = 2

14 – 13 = 1

14 – 14 = 0


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Unit A1

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Plenary• Display the pairs of numbers. Referring to the numbers 17 and 9, ask the class to subtract

the two numbers. Wait about 15 seconds, then invite a child to say the answer. (8) Ask: Who knew the answer? Who had to work it out? How did you work it out?

• Ask: What subtraction fact using multiples of ten do I know the answer to if I know 17 – 9 = 8?

• Record 170 – 90 = 80 on the board.

• Repeat for the other pairs of calculations.

• Say: When you know your subtraction facts by heart you can use them to work outother related calculations.

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• Look at this number sentence. What could the two missing numbers be?� – � = 9

• What is 16 – 5? What other subtraction calculations equal 11?


Fish food numbersPage 10

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L7

Differentiation PackSmiley calculations

SCM 4

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Adding multiples of ten

Main teaching• Display the counting stick. Count on in tens to 100 and back.

• Ask: How many tens are there in 40? (4) How many in 70? (7)

• Write 100 on the board. Ask: How many tens are there in 100? (10)

• Say: One hundred is the same as ten tens. Count the division on thecounting stick.

• Say: It is very useful to know all the multiples of 10 that, added together,equal 100. We can use our addition facts for 10 to help us with this.

• Say: Tell me two numbers that go together to make 10. Record a child’sresponse on the board e.g. 4 + 6.

• Say: As we know 4 plus 6 equals 10, we also know that 40 add 60 equals100. Write this on the board as an addition calculation alongside 4 + 6, e.g. 40 + 60 = 100. Point and say: Four tens add six tens equals ten tens.

• Repeat with other addition facts for 10, e.g. 0 + 10, 1 + 9, 2 + 8, 3 + 7, 5 + 5,until you have a complete list of all the multiples of 10 that add together tomake 100 written on the board.

• Display the pairs of multiples of 10 that total 100. Ask: What multiples of 10are missing?

• Reveal the missing multiple of 10.

• Repeat the above until all the pairs of multiples of 10 that total 100 arerevealed.


Vocabulary multiple; hundreds; add; plus; total; sum; equals

Objective • Derive and recall pairs of multiples of 10 that total 100

SoftwareTeach A1 L8

0 + 10 0 + 100

1 + 9 10 + 90

2 + 8 20 + 80

3 + 7 30 + 70

4 + 6 40 + 60

5 + 5 50 + 50

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• Tell me two multiples of 10 that total 100.

• Can you tell me all the pairs of numbers that equal 100?

Plenary• Write 100 on the board.

• Say: I am going to call out a multiple of 10. I want you to reply with the multiple of 10that goes with it to make 100. So if I say 30, you answer 70. Encourage quick responses.

• Say: Knowing all the multiples of 10 that go together to make 100 will make othercalculations easier.


Balloon tensPage 11


L8

HomeworkHomework Pack

Pick up 10sHCM 3

Resources scissors

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Mental addition

Main teaching

• Say: Today we are going to look at mental calculation strategiesfor addition.

• Display 6 + 18 =.

• Say: I am going to explain how I would add these two numbers together.First I put 18 in my head because it is the larger number. Then I need toadd on the 6. I add on 2 to get 20, now I add on the remaining 4 of the 6.20 add 4 totals 24. So 18 add 6 equals 24.

• Record your steps on the board using the empty number line and ascalculations:

6 + 18 = 18 + 2 = 20

20 + 4 = 24

• Point to 6 + 18 = and say: I could have worked it out in this order too, butputting the larger number first makes it easier as there is less to add on.

• Display 7 + 25 =. Ask children to add the two numbers together, showing theirworking on their paper.

• Choose a child to explain their method and to write their calculation on theboard. Ask: Why did you put that number first? What is the next multipleof ten that you need to jump to? Did anyone work it out using a differentmethod? Show us what you did.

• Continue using different calculations. Encourage jumping to the tens boundaryrather than counting on in ones when adding a one-digit number.


Vocabulary add; addition; plus; sum; total; altogether; equals; sign

Objective • Add mentally combinations of one-digit and two-digit numbers

SoftwareTeach A1 L9

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2

Unit A1

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3–5

18 20

+2 +4

24


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Homework

• Look at �5 + 8 = ��. How many different ways can you complete it? What is the same about all the calculations?

Plenary• Display the two calculations and ask: How can knowing 8 add 4 equals 12 help me to

work out 18 plus 4?

• Continue the pattern of calculations up to 98 + 4, e.g. 28 + 4, 38 + 4 and so on.

• Ask: What is the same about all the answers? (units digit) What is different about all theanswers? (tens digit)

Pupil activities

Homework PackCatching stars

HCM 4

Pupil Book 3AFairground addition

Page 12

6


L9

Differentiation PackFruit addition

ECM 3

80

Mental subtraction

Main teaching

• Say: Today we are going to look at mental calculation strategies forsubtraction.

• Display 24 – 7 =.

• Say: I am going to explain how I would work out this subtraction. First Isubtract 4 to get to 20 then I subtract the remaining 3 of the 7, 20subtract 3 equals 17.

• Record your steps on the board using an empty number line andas calculations:

24 – 7 = 24 – 4 = 20

20 – 3 = 17

• Display 45 – 8 =. Ask children to work out the calculation, showing theirworking on their paper.

• Choose a child to explain their method and to write their calculation on theboard. Ask: How did you work out the answer to this calculation? Did anyone work it out using a different method? Show us what you did.

• Continue using different calculations. Encourage jumping to the tens boundaryrather than counting back in ones when subtracting a one-digit number.


Vocabulary take away; subtract; minus; fewer; less; difference; equals

Objective • Subtract mentally combinations of one-digit and two-digit numbers

SoftwareTeach

A1 L10

1

2

Unit A1

10Lesson

17 20

–3 –4

24


3–5

81

• Look at this calculation �2 – 7 = ��. How many different ways can you complete it?What is the same about all the calculations?

Plenary• Display the two calculations and ask: How can knowing 14 subtract 6 equals 8 help me to

work out 24 subtract 6?

• Continue the pattern of calculations up to 94 – 6 =, e.g. 34 – 6 =, 44 – 6 = and so on.

• Ask: What is the same about all the answers? (units digit) What is different about all theanswers? (tens digit)


Subtraction jugglingPage 13

6

Differentiation PackSubtraction grids

ECM 4


L10

adec mathematics curriculum 2011 cnpm 3 objectives ... · counting, partitioning and calculating a1...

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