Vocabulary
( 2 + 5 ) + 1 = 2 + ( 5 + 1 )
Associative Property of Addition
What is 9+19
28
What is 32+68
A horse weighs 1,723 pounds. A smaller horse weighs 902 pounds. How much do both horses weigh together?
2,625 pounds
Round to the nearest 10 then add:
198 + 132
200 + 130 = 330
12 + 15 = 15 + 12
Commutative Property of Addition
What is 29+67
96
What is 30+89
119
Brandon scores 107 points in Fortnite. Jaden scores 111 points in the same game. How many points do they score in all?
218
Round to the nearest 10 then add:
725 + 229
730 + 230 = 960
3 + 0 = 3
Identity Property of Addition
What is 57+32
89
What is 405+23
428
Briella bakes 10 snacks for a bake sale. Santiago bakes 33 snacks for the bake sale. How many snacks do they bake in all?
43
Round to the nearest 10 then add:
43 + 82
40 + 80 = 120
Ordering or grouping numbers so they are easier to add in your head.
Mental Math
What is 14+78
92
What is 11+ 89
100
A golf ball has 336 dimples. How many dimples would there be in 3 golf balls?
1,008
Round to the nearest 100 then add:
1,274 + 3,599
1,300 + 3,600 = 4,900
A set of numbers that follows a certain order
Pattern
What is 30 + 30
60
What is 230+40
270
Santiago has 245 books. Alex gives him 80 books to add to his collection. But... Mr. Justin decides to steal their entire collection and add it to his existing 15 books. How many books does Mr. Justin have now (muahahaha).
340
Round to the nearest 100 then add:
8,291 + 1,101
8,300 + 1,100 = 9,400