Decompose to Add
How can you decompose the SECOND addend to make a 10 with the first addend?
9 + 7 = ?
9 + (1 + 6)
USE A NUMBERLINE TO ADD:
34 + 45
80
27 + 65
65 + 27
92
Use Base Ten Blocks to help you add:
A roller coaster has 32 red cars and 29 blue cars. How many cars does the roller coaster have in all?
III oo
II ooooooooo
61 cars
USE EXPANDED FOR to decompose the addends to add:
22 + 48
20 + 2
40 + 8
60 + 10 = 70
How can you decompose the second addend to make a double for the first addend?
6 + 8
6 + (6 + 8)
Use a number line to help to add 9 + 8
17
Zofia counts 24 shells, 17 crabs, and 19 starfish at the beach. How many shells, crabs, and starfish does Zofia count in all?
60 things
Aisha uses 29 star stickers and 23 flower stickers to make a craft. Aisha says she uses 50 stickers in all. How do you respond to Aisha? Use Base Ten blocks to explain
stars-IIooooooooo
flowers-IIooo
Total she uses52 stickers, not 50.
How can you use expanded form to add:
Florian folds 38 paper flowers. Max folds 25 paper flowers. How many paper flowers do Florian and Max fold in all?
38 -> 30 + 8
25 -> 20 + 5
63 <- 50 + 13
SHOW ALL THE WAYS you can adjust addends to add:
72 + 19
70 + 21
71 + 20
Us e a number line to help you add:
Mr. Lee buys 26 thin paintbrushes and 35 thick paintbrushes. How many paintbrushes does Mr. Lee buy in all?
61 paintbrushes
On Saturday, Jimin spends 26 minutes playing soccer. On Sunday, she spends 15 more minutes playing basketball than she does playing soccer. How many minutes does Jimin spend playing soccer and basketball in all?
Sat-26
Sun-26 + 15 = 41
In all- 26 + 41 = 67
Use expanded form to find the sum:
A tree grows 44 centimeters the first year and 39 centimeters the second year. How many centimeters does the tree grow during the two years?
44 -> 40+ 4
39 -> 30 + 9
83 <- 70 + 13
83 centimeters
How can you decompose one addend to find the sum of 21 + 67?
20 + 68
18 + 70
There are 7 yellow birds and 8 brown birds at a park. Use a doubles fact to help you find the total number of birds at the park.
7 + 8
7 + (7 + 1) = 15 birds