Give an example of the Identity Property using a number sentence.
Example: 6+0=6
100
George weighs 97 pounds. His older sister Mary weights 145 pounds. Which is a reasonable estimate for how much the two brothers weigh in all?
100 + 150 = 250
100
Emily subtracts 34 from 170 and gets 136. Which number should she add to 136 to check her answer?
34
100
Use a number line to solve:
27 + 68 + 9.
104
200
Show how to solve the problem: 390-273 using mental math.
One way: 400-283=117
390+10=400
273+10=283
200
24+(60+2)=2+(60+24) is an example of which property of addition?
Associative
200
There are 489 students who attend Spring Valley Elementary School 307 of the students bring their lunch. Estimate how many students buy their lunch from school.
About 200 students buy lunch.
200
Alexis found 478+512. Her answer was 990. Show how you can check her answer.
478+512=990
990-512=478
200
Lauren is making a scrapbook. She has 32 photos of friends and 46 photos of family. How many photos does she have altogether? Use a strip diagram to solve.
78 photos
300
Joseph wants to use mental math to add 410 and 673. How could Joseph break apart these numbers into hundreds, tens, and ones to make the problem more simple?
Break 410 into 400+10
and break 673 into 600+70+3
300
Noel wrote this number sentence:
68+95=95+68
Which Property of Addition did Noel write?
Commutative Property
300
Lilly has 98 dollars and Max has 289 dollars. Use estimating to find about how many dollars they have combined.
About $400.00
300
Drew subtracted 454 from 888. How can he check his work using inverse operations?
888-454=434
434+454=888
300
Emanuel saw 31 fish and 29 gulls at the beach. How many animals did Emanuel see in all? Use a strip diagram to solve.
60 Animals
400
Use mental math to solve this problem:
854-539
315
400
Bob modeled the addition property with the equation below:
38+0= ______
What property is he modeling? What is the missing number?
Identity, 38
400
Heather is adding 831 and 262. Estimate the sum of these two numbers to the nearest hundred.
800+300=1,100
400
Inverse operations help us _________.
Check our work.
400
Use the number line to solve 55 + 47 − 9.
93
500
Miss. Arbogast bought 38 red markers and 23 black markers. She needs 27 more red markers. Use mental math to determine how many red markers Miss. Arbogast needs.
65 Red markers
500
Greyson wants to find the sum of 15+40+10. Write a number sentence using the associative property of addition to solve this addition problem.
(15+10)+40=65
500
Holly has 32 pennies and James has 458 pennies. Holly wants to estimate how many pennies she and James have. What compatible numbers should she use to get a reasonable estimate?
30 and 450
500
David added 459+209 and got 668. Show how he can use the inverse operation to check his answer.
459+209=668
668-209=459
500
Alex had 74 action figures in his collection before 19 of them were destroyed. How many action figures does Alex now have? Use a strip diagram to solve.