1. Using Models to Add Decimals
5.NBT.B.7

2. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What decimal does this represent? Let’s find out how many of the 100 squares are red. 10 20 30 31 32 33 34
This model represents the fraction 34 hundredths …
… and the decimal 34 hundredths. 34
100 =
0.34
This model represents the fraction 34 hundredths …
… and the decimal 34 hundredths. 34 31 10
What decimal does this represent? Let’s find out how many of the 100 squares are red. 20 30 32 33

3. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What decimal does this represent? Let’s find out how many of the 100 squares are red. 10 20 21 22
This model represents the fraction 22 hundredths …
… and the decimal 22 hundredths. 22
100 =
0.22
… and the decimal 22 hundredths.
This model represents the fraction 22 hundredths … 21
What decimal does this represent? Let’s find out how many of the 100 squares are red. 10 20 22

4. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What decimal does this represent? Let’s find out how many of the 100 squares are red. 1 2 3 4 5 6
This model represents the fraction 6 hundredths …
… and the decimal 6 hundredths. 6
100 =
0.06
This model represents the fraction 6 hundredths …
… and the decimal 6 hundredths. 6 4
What decimal does this represent? Let’s find out how many of the 100 squares are red. 1 2 3 5

5. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What decimal does this represent? Let’s find out how many of the 100 squares are red. 10 20 30 40 50 51 52 53 54 55 56
This model represents the fraction 56 hundredths …
… and the decimal 56 hundredths. 56
100 =
0.56 56 55 54
… and the decimal 56 hundredths.
This model represents the fraction 56 hundredths … 51 20 10
What decimal does this represent? Let’s find out how many of the 100 squares are red. 30 40 52 50 53

6. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent? 23
100 14
100 + =
14 hundredths
How much more is this?
Here is 23 hundredths.
What is the sum of these numbers?

7. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
Here is 23 hundredths.
How much more is this?
14 hundredths
What is the sum of these numbers?
Let’s break the numbers apart to find out.
Let’s join the ones together …
… and join the tens together. Now we can count. 10 20 30 31 32 33 34 35 36 37
This represents the fraction 37 hundredths …
… and the decimal 37 hundredths. 23
100 14
100 37
100 + = =
0.37 37
… and the decimal 37 hundredths.
This represents the fraction 37 hundredths … 35 10
… and join the tens together. Now we can count.
Let’s join the ones together …
Let’s break the numbers apart to find out. 20 30 34 33 32 31 36

8. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
How much of the large square is shaded?
44 hundredths
What part of the large square is this?
27 hundredths
What is the sum of these two numbers? 10 20 30 40 50 60 61 62 63 64 65 66 67 68 69 70 44
100 27
100 71
100 + = =
0.71 68 69 67 66 65 70 71
… and the decimal 71 hundredths.
This represents the fraction 71 hundredths …
44 hundredths 64
What part of the large square is this? 62 20 30 60 50 10
How much of the large square is shaded? 40 61
What is the sum of these two numbers?
27 hundredths 63

9. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What part of the large square is this?
32 hundredths
How much more is this?
15 hundredths
What is the sum? 10 20 30 40 41 42 43 44 45 46 47
This represents the fraction 47 hundredths …
… and the decimal 47 hundredths. 32
100 15
100 47
100 + = =
0.47 47
This represents the fraction 47 hundredths … 46
… and the decimal 47 hundredths. 45
What is the sum? 10
15 hundredths
How much more is this?
32 hundredths 20 30 43 44 42 41 40
What part of the large square is this?

10. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What part of the large square is this?
37 hundredths
How much more is this?
36 hundredths
What is the sum?
Here are 37 hundredths …
47 hundredths …
57 hundredths … 67 68 69 70 71 72
73 hundredths
This represents the fraction 73 hundredths …
… and the decimal 73 hundredths. 37
100 36
100 73
100 + = =
0.73
37 hundredths
How much more is this?
36 hundredths
47 hundredths …
57 hundredths … 67
What is the sum?
What part of the large square is this? 69
This represents the fraction 73 hundredths …
73 hundredths 72
… and the decimal 73 hundredths. 70 71
Here are 37 hundredths … 68

11. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What part of the large square is this?
13 hundredths
How much more is this?
64 hundredths
What is the sum?
Here are 64 hundredths …
74 hundredths … 75 76
77 hundredths
This represents the fraction 77 hundredths …
… and the decimal 77 hundredths. 13
100 64
100 77
100 + = =
0.77
What is the sum?
64 hundredths 76 75
74 hundredths …
How much more is this?
13 hundredths
… and the decimal 77 hundredths.
This represents the fraction 77 hundredths …
77 hundredths
What part of the large square is this?
Here are 64 hundredths …

12. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What part of the large square is this?
3 hundredths
How much more is this?
42 hundredths
What is the sum?
Here are 42 hundredths …
43 hundredths …
44 hundredths …
45 hundredths
This represents the fraction 45 hundredths …
… and the decimal 45 hundredths. 3
100 42
100 45
100 + = =
0.45
How much more is this?
42 hundredths
What is the sum?
3 hundredths
43 hundredths …
Here are 42 hundredths …
… and the decimal 45 hundredths.
This represents the fraction 45 hundredths …
44 hundredths …
45 hundredths
What part of the large square is this?

13. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What part of the large square is this?
12 hundredths
How much more is this?
24 hundredths
13 hundredths
What is the sum? 10 20 30 40 41 42 43 44 45 46 47 48 49
This represents the fraction 49 hundredths …
… and the decimal 49 hundredths. 12
100 24
100 13
100 49
100 + + = =
0.49
How much more is this? 47 48 49
13 hundredths
… and the decimal 49 hundredths. 20 30 40
What is the sum?
This represents the fraction 49 hundredths …
12 hundredths 42 43 46 45 10 41
How much more is this? 44
What part of the large square is this?
24 hundredths

14. Using Models to Add Decimals
Closing Question

15. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
What part of the large square is this?
9 hundredths
How much more is this?
16 hundredths
25 hundredths
What is the sum? 9
100 16
100 25
100 + + =
25 hundredths
How much more is this?
9 hundredths
What part of the large square is this?
How much more is this?
16 hundredths
What is the sum?

16. What decimal does this represent?
Using Models to Add Decimals
What decimal does this represent?
Let’s decompose these shapes to find out. 10 20 30 40 50
This represents the fraction 50 hundredths …
… and the decimal 50 hundredths. 9
100 16
100 25
100 50
100 + + = =
0.50 30 20 10
… and the decimal 50 hundredths.
This represents the fraction 50 hundredths … 50 40
Let’s decompose these shapes to find out.