module 4
DESCRIPTION
Module 4. Lesson 4. Objective. Add and subtract multiples of 10 and some ones within 100. Place Value. Say the number. What digit is in the tens place? What’s the value of the 7? State the value of the 1. State the place of the 4. - PowerPoint PPT PresentationTRANSCRIPT
Place Value
• Say the number. • What digit is in the tens place? • What’s the value of the 7? • State the value of the 1. • State the place of the 4. • Let’s try some more by asking the same questions.
174
258 734 860 902
Making a Ten Drill
• 7 + ___ = 10 • Let’s find missing parts to make ten. If I say 7, you would
say 3. • Ready? 7. • Say the number sentence. • Let’s try some more numbers:
23 27 42 48 58
4 3 7 17 13
Making the Next Ten to Add
• When I say, 9+4, you say 10+3. • Ready? 9+4. • What’s the answer?
• Let’s try some others:
19+4 8+5
48+3
18+3
8+3
59+6
29+6
19+6
9+6
79+4
49+4
29+4
67+4
17+4
7+4
27+6
17+6
7+6
88+5
18+5
Concept Development• There are 5 yellow cubes. How many
linking cubes am I showing in this stick? • How many in this stick? • What is the difference between 8 and 5? • What number sentence could I use to
represent the difference between 8 and 5?
• 8–5=3.
Concept Development Continued
• Has the difference changed? • But what new number sentence can I use to represent the difference between my two sticks?
• 9–6=3. • Is the difference still 3? • YES!
Concept Development Continued• If I add more to each bar. Did the
difference change? • Let’s test this idea. When we add the
same amount to each number in a subtraction sentence, the difference stays the same.
• Now let’s try this with a new problem. 34 – 28
• Now that is challenging! • Try this one: 36 – 30. • How did you know the answer so
fast? • Yes! Is it easier to subtract just tens!
Concept Development Continued• Now, can you tell me how
34 – 28 and my other problem, 36 – 30, are related? Turn and talk. • Now how long is each bar? • We added 2 to each bar to
make the problem easy! • Now it’s your turn. On your
white board, solve these problems by making a tape diagram. Add on to both numbers to make the problem easier.
22-8
26-19
33-18
Concept Development Continued• There are 6 red cubes on one end
and 4 red on the other end. How many yellows are in the middle?
• What is the total number of cubes? • Let’s make 2 different addition
sentences. What is the addition sentence for the total number of cubes?
• Now instead let’s join the 1 yellow with the 6 red.
• How do you know this is true
6+5 = 7+4?
Concept Development Continued• Let’s use that same idea with
larger numbers to make tens. • Let’s solve 28 + 36. • What does 28 need to be the next
ten? • What is 2 less than 36? • How do you know this is true:
28+36=30+34? • We can also show 2 more for 28
with our number bond. • Let’s write both models in our
journals and explain them to your partner.
Concept Development Continued
•Let’s do some more practice with the following problems:
19+35
37+4678+24
36+29