Properties of Addition
Which property of addition is shown in the number sentence (2+3) + 5 = (3+5) + 2?
Associative property of addition
Use a mental math strategy to answer the following problem:
29 + 45 = ?
74
Write 2 addition and 2 subtraction problems for the fact family 9, 1, & 8.
1 + 8 = 9
9 - 1 = 8
9 - 8 = 1
Rex has 252 football cards and 596 baseball cards. Which number sentence shows the best estimate of how many cards Rex has in all, using compatible numbers?
A. 300 + 500 = 850
B. 300 + 500 = 800
C. 250 + 550 = 800
D. 250 + 600 = 850
D. 250 + 600 = 850
Tom had $41. He spent $17. Which is the best estimate of how much he had left?
A. $60
B. $30
C. $20
D. $10
C. $20
Which property of addition is shown in the number sentence 31 + 0 = 31?
Zero property or Identity property
Use a mental math strategy to answer the following problem:
107 = 83 = ?
190
Write 2 addition and 2 subtraction problems for the fact family 17, 5, & 12.
5 + 12 = 17
12 + 5 = 17
17 - 5 = 12
17 - 12 = 5
Which WAYS show how to estimate the sum of 465 + 313? (More than one).
A. 500 + 300
B. 470 + 310
C. 600 + 400
D. 465 + 310
A, B, & D
A zoo has 52 kinds of snakes and 12 kinds of lizards. Estimate how many more kinds of snakes than lizards are in the zoo.
50 - 10 = 40
Which property of addition is shown in the number sentence 7 + 4 = 4 + 7?
Commutative Property of Addition
Tropical Fish Warehouse had 98 goldfish on Monday. By Friday, they had sold 76 goldfish. How many goldfish had not been sold? Use mental math to solve.
98 - 76 = 22
Which of the following does not belong:
A. 11 + 2 = 13
B. 13 - 2 = 11
C. 13 + 11 = 24
D. 13 - 11 = 2
C. 13 + 11 = 24
Kaitlyn read a 48-page book. Her sister read a 104-page book. About how many total number of pages did the sisters read?
150 pages
(48 rounds to 50, 104 rounds to 100)
Round to the nearest hundred to estimate the difference:
398 - 129 = ?
400 - 100 = 300
Which property of addition is shown in the number sentence 73 + (81 + 2) = (73 + 81) + 2?
Associative Property of Addition
Kal spent 28 minutes on math homework and 43 minutes on science homework. Use mental math to find how much more time he spent on science than on math.
Which of the following does not belong:
A. 304 - 28 = 276
B. 276 + 304 = 580
C. 304 - 276 = 28
D. 276 + 28 + 304
B. 276 + 304 = 580
Round to the nearest hundred then estimate:
198 + 426 = ?
200 + 400 = 600
Shawn had 342 cards. He gave 128 cards to his sister. Estimate how many cards he had left. Round to the nearest ten to estimate your answer.
340 + 130 = 470
Which property of addition is shown in the number sentence 4,780 + 0 = 4,780?
Zero Property or Identity Property of Addition
Lee drove 348 miles on Monday and 135 miles on Tuesday. Is 313 miles a reasonable answer for how much farther Lee drove on Monday than on Tuesday? Explain
No...if you round 348 to 350 then subtract 135, it is only 215.
Write all four number sentences for the fact family 29, 17, & 46.
29 + 17 = 46
17 + 29 = 46
46 - 29 = 17
46 - 17 = 29
Round to the nearest ten to estimate:
28 + 384 = ?
30 + 380 = 410
Round to the nearest ten to estimate the difference:
1,264 - 132 = ?
1,260 - 130 = 1,130