Maths:Addition and Subtraction!

Summer Term 6 Week 3

Learning objectives...We are going to be looking at addition and subtraction. We will look at strategies you can do in your head but also ones you can write down to complete:

I can add and subtract whole numbers with more than 4 digits, including using formal written methods (columnar addition and subtraction)

I can add and subtract numbers mentally with increasingly large numbers

I can use rounding to check answers to calculations and determine, in the context of a problem, levels of accuracy

I can solve addition and subtraction multi-step problems in contexts, deciding which operations and methods to use and why.

Monday - Activity 1 starter - LO: I can complete simple calculations in my headComplete these calculations in your head… think carefully about the columns you will be interested in (units, tens, hundred, thousands?) i.e. for 34 - 10 you would only be interested in the tens column as you’re subtracting 10 which has NO units.

1 chilli:

1. 34 - 10 = 2. 67 - 20 = 3. 120 + 20 = 4. 334 + 50 = 5. 65 - 30 = 6. 1234 + 300 =

2/3 chilli:

1. 809 + 640 = 2. 1314 - 200 = 3. 6008 + 3400 = 4. 17 524 + 4100 = 5. 782 - 550 = 6. 1297 + 600 = 7. 2417 - 900 = 8. 8001 - 2800 =

Check your answers with a calculator and correct

any mistakes with a different coloured pen.

Monday - Activity 1 - LO: I can solve addition and subtraction questions mentallyBeing able to add and subtract mentally is a brilliant skill to have. However, it’s really important to know WHEN you should add mentally and WHEN you should use a written method.

Adding and subtracting in your head is a good idea when you’re dealing with near multiples. What is a near multiple I hear you cry! A near multiple is a number that is close to 10, 100 or 1000 (depending on the size of the number).

For example...Our question: 4658 + 198 = ?

198 is very close to 200! In fact, it’s only 2 off! So, let’s add 2 to 198 to make it 200 (a present from us to us). This makes our sum much easier and something we could do in our heads:

Our question has now become: 4658 + 200 = ?

Now, we are concerned only with the hundreds column as we’ve cleared the tens and units columns:

4658 + 200 = ?

6 + 2 = 8 so 4658 + 200 = 4858!

BUT! We mustn’t forget to take away the 2 we had previously gifted ourselves. Our final sum will be 4858 - 2 = 4856!

So… 4658 + 198 = 4856!

You could visualise this as a number line. In your head, sketch a number

line to show 4658 with a jump of 200, and a small hop back of 2 from 4858.

Obviously all this is written down but you would be doing it

in your heads (it looks much more complicated than it is

written down)!

There are other mental strategies … Now you’ve had a go at one properly, it really is up to you to decide which suits you and your brain best! https://www.youtube.com/watch?v=ne2hWydMt-o

Watch this video as it talks you through a variety of mental strategies. Have a go at one you like to solve the questions below!

1. Split strategy 2. Compensation strategy 3. Bump strategy

4658 + 132 and 4658 – 237

Monday - Activity 1 - LO: I can solve addition and subtraction questions mentally

1 chilli - choose 5 rows of sums to complete mentally (or with minimal jottings) from the green box 2 chilli - choose 8 rows of sums to complete mentally (or with minimal jottings) from across the green and blue box 3 chilli - choose 10 rows of sums to complete mentally (or with minimal jottings) from across the green and blue box.

Check your answers with a calculator and correct any mistakes with a different

coloured pen.

It’s useful to be able to visualise links between numbers and how they could be equivalent. The equals sign means that anything either side has to be the same. Use your multiplication knowledge and number bonds to make the equations balance (be equal on both sides).

Extension… Check your answers with a calculator and

correct any mistakes with a different coloured pen.

Tuesday - Activity 2 starter - LO: I can understand mathematical terminology and quickly apply my addition and subtraction knowledge

As quickly as you can, complete the questions on the right. If you want to, time yourself to see how quickly you manage it!

Finding the difference = subtractionTotal of = additionLess = subtraction Sum of = addition More than = addition Much more than = subtraction Difference between = subtraction

Tuesday - Activity 2 - LO: I can use column addition (a formal written method)https://www.youtube.com/watch?time_continue=43&v=5nex9ScUclU&feature=emb_logo

Watch the video above to remind yourself of how to lay out column addition and how to use it correctly.

You do not have to write out your

addition like they have in the video as you should be able to do this in your head. However, if it helps you to for the

first few times, please feel free to.

You do not have to write the Th, H, T or

U as column headers BUT YOU MUST make sure you are carefully presenting your workings in neat

columns. It will stop you from making

silly mistakes.

1 chilli complete all the questions using column addition and the challenge if you want to.

Remember to take the time to line your numbers up CAREFULLY! This could be the difference between getting the right or wrong answer.

Check your answers with a calculator and correct any mistakes with a different coloured pen.

Tuesday - Activity 2A - LO: I can use column addition (a formal written method)

2 chilli - complete 1 - 8 and the challenge if you want to.

3 chilli - complete all questions and the challenge

Remember to take the time to line your numbers up CAREFULLY! This could be the difference between getting the right or wrong answer.

Check your answers with a calculator and correct any mistakes with a different coloured pen.

Tuesday - Activity 2A - LO: I can use column addition (a formal written method)

The same principles apply for adding numbers with decimals. Decimals are found in money and measurements so it’s useful to practise as you will meet these frequently in day to day life. You MUST line all the decimals up in order to accurately add them together.

1 chilli - complete questions 1-6

2 chilli - complete questions 1 - 8

3 chilli - complete questions 1-8 and the challenge.

Check your answers with a calculator and correct any mistakes with a different coloured pen.

Tuesday - Activity 2B - LO: I can use column addition for decimals (a formal written method)

Extension… 1. Mr Green drives a truck. Last week he drove 197 kilometres, 232 kilometres and 164 kilometres on his 3 journeys.

This week he drove 309 kilometres and 265 kilometres on his 2 journeys.

What was the difference in kilometres between this week and last week?

4. Over the weekend, Paulina spends 85 minutes on her project and 45 minutes on her maths homework.

On Monday, she spends 65 minutes on her spelling and grammar homework.

Explain how you would work out how much longer she spends on her homework over the weekend. Can you find more than one method?

6. Isla buys a T-shirt for £4.50, a skirt for £8 and a pair of shorts. She pays for the items with a £20 note and gets the following coins as change.

£2 20p 5p

How much were the shorts?

Wednesday - Activity 3 starter - LO: I can work out basic addition and subtraction in my head 1 chilli: 2 chilli: 3 chilli:

Wednesday - Activity 3 - LO: I can use column subtraction (a formal written method)https://www.youtube.com/watch?v=Y6M89-6106I

This is a super useful video - make sure you watch it to the end as it helps you to deal with crossing tens and borrowing!

With subtracting, you must still make sure your numbers are lined up neatly in their columns.

1 & 2 chilli

Wednesday - Activity 3 - LO: I can use column subtraction (a formal written method)

Check your answers with a calculator and correct any mistakes with a different coloured pen.

3 chilli

Wednesday - Activity 3 - LO: I can use column subtraction (a formal written method)

Check your answers with a calculator and correct any mistakes with a different coloured pen.

Extension…

I was trying to practise my column subtraction but I don’t think I’ve cracked it yet… Can you help?

1. Explain where I’ve gone wrong in each example and then do it correctly

2. If you think I’ve done it correctly (yay me), then prove it using the inverse operation.

3. You can get bonus points if you can show me how using estimation would have helped to show me that i was wrong!

Thursday - Activity 4 starter - LO: I can apply my knowledge of addition and subtraction and choose a method that suits me to solve a problem

Use your code breaking skills to solve the problems! 1 chilli - solve questions 1 - 5 from the red box, 2 chilli - solve 2 questions from the red box and 3 from the blue box, 3 chili - solve all 6 questions from the blue box. Check with a calculator.

Thurs - Fri Shape!A whistle stop tour of the properties of shapes

with a sprinkling of angles.

Thursday - Activity 4 starter - LO: I can identify polygons based on regular and irregular properties

https://www.youtube.com/watch?v=IaoZhhx_I9s ← watch me!

Polygon = A polygon is any 2D shape formed with straight lines. Triangles, quadrilaterals, pentagons, and hexagons are all examples of polygons. The name tells you how many sides the shape has. For example, a triangle has three sides, and a quadrilateral has four sides. Tri means three and quad means four! Pretty cool, huh?

Polygons can be sorted based on whether they are regular or irregular.

A regular polygon has sides equal in length and angles equal in size! If the shape has only straight sides, has all its sides the same length and has all its angles the same length then it is a regular polygon! Simple!

An irregular polygon will have lengths that are different lengths and angles that are not all the same. For example, it may have a mixture of acute (smaller than 90 degrees) and obtuse (bigger than 90 degrees) angles.

Task: sort the shapes into the Venn diagram. 3 chilli - sort into the Carroll diagram as well!

If you want to print the shapes out and physically sort them, that’s great. You could also number the shapes and put

the corresponding number into the

diagram. I wouldn’t

recommend drawing them as

some of the shapes look quite similar to each

other!

Thursday - Activity 4A - LO: I can identify 3D shapes based on 2D representationsWe often have to represent or recognise 3D shapes in a 2D way. For example, drawing a net for a octagonal prism or noticing that we are looking at a cube from a drawing would require us to be able to identify 3D shapes in a 2D representation.

Have a go at the questions on the following slide...

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3 chilli extra challenges

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Extension…

Friday - Activity 5 starter - LO: I can identify and estimate acute, obtuse and reflex angles

1. What is an acute angle?2. What is a right angle?3. What is an obtuse angle?4. What is a reflex angle?

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https://www.youtube.com/watch?time_continue=26&v=Ld6lgwssZys&feature=emb_logo ← have a listen to refresh your angle facts (it is without doubt the worst song you will hear all day so I can only apologise - I’m sorry year 5 - but it is full of need to know info I promise!)

Friday - Activity 5 - LO: I can apply my knowledge of angles to solve problemsAfter watching the video clip on the previous page, answer the following questions:

Questions to answer

1. What unit do we use to measure angles?2. How can we tell whether an angle is acute?3. Where would you place your protractor when measuring an angle?

Second task:

1 chilli - choose 2 from each page to complete (make sure you write down the question number)!

2 chilli - choose 3 from each page to complete (make sure you write down the question number)!

3 chilli - complete the 8 angle challenges and then choose 2 of the 3 chilli challenges to complete (make sure you write down the question number)!

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3. 4.

5. 6.

8. 7.

3 chilli challenges...

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Have the best weekend year 5!