Reasonable Answers and Decimal
Problems
Unit 5 Lesson 5
Solve:
98.4 + 23.65 =
Solve:
77.632 − 9.3 =
Estimate the answer by rounding each number to the nearest tenth
and adding or subtracting.
A male giraffe at the zoo weighs 963.87 pounds. A female giraffe at the same
zoo weighs 793.9 pounds.
Sierra says the male giraffe weighs 884.48 pounds more than the female giraffe.
Is her answer reasonable compared to your estimate?
Estimate the answer by rounding each number to the nearest tenth
and adding or subtracting.
When Zoe’s puppy was born, it weighed 8.25 pounds. When it went for its
one-year check-up, it weighed 43.8 more pounds.
Zoe says her puppy now weighs 12.63 pounds. Is her answer reasonable compared to
your estimate?
Estimate the answer by rounding each number to the nearest tenth
and adding or subtracting.
897.26 + 392.65 =
897.26 + 392.65 = 1,192.9
Estimate the answer by rounding each number to the nearest tenth
and adding or subtracting.
61.35 − 35.86 =
61.35 − 35.86 = 97.21
Estimate the answer by rounding each number to the nearest whole
number and adding or subtracting.
Jason drove 12.5 km to the ballpark and then 1.825 km to the
bank. What was the total distance he drove?
Jason thought the answer was 30.75 km. Is his answer reasonable
compared to your estimate?
Estimate the answer by rounding each number to the nearest whole
number and adding or subtracting.
Sophie rode her bike 16.135 km and walked 5.865 km. How much
farther did she ride her bike than she walked?
Sophie thought the answer was 22.000 km. Is her answer reasonable
compared to your estimate?
Choose the answer.
Choose the answer.
Choose the answer.
Jonathan said that 452.6 + 59.83 equals
1,050.9. Is Jonathan’s answer reasonable?
A.
B.
C.
D.
Yes, Jonathan’s answer is reasonable.
No, the answer is about 500.
No, the answer is about 600.
No, the answer is about 900.
Choose the answer.
Greg said that 913.46 − 199.5 equals 893.51. Is Greg’s answer
reasonable?
A. Yes, Greg’s answer is reasonable.
B . No, the answer is about 700.
C . No, the answer is about 1,000.
D. No, the answer is about 1,100.
Choose your answer.
Choose your answer.