Open Number Line
Draw an open line to show 23+43
66
How can you use compensation to find the sum? Then solve.
27 + 46 = ___
a. I can take 3 from 46 and add it to 27 to get 30 + 43 = 73. So 27 + 46 = 73.
b. I can take 6 from 46 and add 3 to 27 to get 40 + 30 = 70. So 27 + 46 = 70.
c. I can add 4 to 46 and subtract 2 from 27 to get 50 + 25 = 75. So 27 + 46 = 75.
d. I can add 4 to 46 and add 3 to 27 to get 50 + 30 = 80. So 27 + 46 = 80.
a. I can take 3 from 46 and add it to 27 to get 30 + 43 = 73. So 27 + 46 = 73.
Break apart the second addend to solve 45+27
45+27
20+7= 27
45+20=65
65+7=72
40+38
78
Kathy has 44 markers. She gets 25 more markers. How many markers does Kathy have in all? Use any strategy to solve. Show your work.
44 + 25 = 69
69 markers
Draw an open line to show 32+26
58
Which equation shows a way to use compensation to find the sum of 23 + 19?
a. 20 + 20 = 40
b. 21 + 21 = 42
c. 22 + 20 = 42
d. 23 + 20 = 43
b. 22 + 20 = 42
Break apart the second addend to solve 29+31
29+31
30+1=31
29+30=59
59+1=60
20+24
44
Kevin has 27 cards.
He buys 65 cards.
How many cards does Kevin have now?
Break apart the second addend to solve.
Show your work.
Break apart 65 into
60 + 5.
Add tens and ones: 27 + 60 = 87
87 + 3 = 90
90 + 2 = 92
92 cards
Draw an open line to show 65+20
85
Which is equal to 32 + 18? Choose all that apply.
a. 48
b. 30 + 20
c. 30 + 10 + 8
d. 40 + 10
☐ 40 + 8
b. 30 + 20
d. 40 + 10
Break apart the second addend to solve 22+44
22+44
40+4=44
22+40=62
62+4=66
76+19
95
Carol has 27 books. Justin has 15 books. Will all of the books fit on a shelf that can hold 35 books? Use any strategy to solve.
No, there are 42 books and only 35 can fit on the shelf.
27 + 15 = 42
42 is bigger than 35.
Draw an open line to show 47+10
57
Use compensation to find the sum.
28 + 14 + 5 = ?
a. 37
b. 45
c. 47
d. 49
c. 47
Break apart the second addend to solve 23+39
23+39
30+9=39
23+30=53
53+9=62
23+26
49
Abe has 33 pens. Marcy has 57 more pens than Abe. How many pens does Marcy have? Use any strategy to solve. Show your work and explain your thinking.
33 + 57 = ?
Break apart 57 into 50 + 7
33 + 50 = 83
83 + 7 = 90
I can add 33 + 57 by breaking apart 57 into 50 + 7. Then add 33 + 50 = 83. Finally, I can add 83 + 7 = 90. Marcy has 90 pens.
Draw an open line to show 45+44
89
Which have a sum of 71? Choose all that apply.
a. 33 + 28
b. 29 + 42
c. 55 + 42
d. 42 + 29
e. 20 + 51
b. 29 + 42
d. 42 + 29
e. 20 + 51
Break apart the second addend to solve 12+61
12+61
60+1=61
12+60=72
72+1=73
43+18
61
Gail has 57 pennies. She
gets 18 more pennies
from Cara. How many
pennies does Gail
have now? Use any strategy to solve.
57 + 18 = 75
75 pennies