Rounding 10's
Round to the nearest 10
21
20
Round to the nearest 100
321
Addy, Ameila and Sara are baking cookies. Addy bakes 24. Amelia bakes 45. Sara bakes 32. How many cookies did they bake?
A. 24 + 45 + 32 = C
B. 24 + 45 = C
C. 45 + 32 = C
D. 24 - 45 - 32 = C
A
Use a mental math strategy to find this answer
25+26
51
Use rounding to estimate the answer
47+21
70
Round to the nearest 10
59
60
Round to the nearest 100
767
800
Cece and Dylan rode bikes to the park. They rode 22 minutes to the park, then 17 minutes to get ice cream, and finally 12 minutes to get home. How long did they ride altogether?
22+17+12= B
Use a mental math strategy to find this answer
267+103
370
Use rounding to estimate the answer
71+65
140
Round to the nearest 10
173
170
Round to the nearest 100
1869
1900
Ellie, Eli and Finn are setting up chairs in the gym for Whole School. They set up 97 chairs on one side and 78 chairs on the other side. How many chairs did they set up?
97+78=C
Use a mental math strategy to find this answer
58-28
30
Use rounding to estimate the answer
56-12
50
Round to the nearest 10
1784
1780
Round to the nearest 100
5739
5700
Jiraiya, Jenyka, Luar, and Luca are playing a team game. Jiraiya and Jenyka earned 45 points. Luar and Luca earned 56 points. How many more points does Luca and Luar have?
56-45=P
Use a mental math strategy to find this answer
75-24
51
Use rounding to estimate the answer.
173-49
120
Round to the nearest 10
143,281,291
143,281,290
Round to the nearest 100
430,290,109
430,290,100
This month the 6th and 8th graders at Della Elementary School had a contest to see who could read the most books. By the end of the month, the 6th graders read 487 books and the 8th graders read 398 books. How many more books did the winners read?
487-398=B
Use a mental math strategy to find this answer
512-299
Use rounding to find the answer
241+612=
850