Rounding to Nearest 10 and 100 — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
53 rounded to the nearest ten is 60.
Corrected: 53 rounded to the nearest ten is 50 because 3 is less than 5 so we round down.
The ones digit in 53 is 3, which is less than 5, so you round down to 50. The original answer of 60 rounded up by mistake.
2. Fix the sentence:
66 rounded to the nearest ten is 60.
Corrected: 66 rounded to the nearest ten is 70 because 6 is 5 or greater so we round up.
The ones digit in 66 is 6, which is 5 or greater, so you round up to 70. The original answer of 60 rounded down by mistake.
3. Fix the sentence:
45 rounded to the nearest ten is 40.
Corrected: 45 rounded to the nearest ten is 50 because when the digit is exactly 5 we round up.
When the ones digit is exactly 5, the rule says to round up. So 45 rounds up to 50, not down to 40.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. 41 rounded to the nearest ten is 40.
The ones digit in 41 is 1, which is less than 5, so you round down to 40.
2. 87 rounded to the nearest ten is 90.
The ones digit in 87 is 7, which is 5 or greater, so you round up to 90.
3. 58 rounded to the nearest ten is 60.
The ones digit in 58 is 8, which is 5 or greater, so you round up to 60.
4. 72 rounded to the nearest ten is 70.
The ones digit in 72 is 2, which is less than 5, so you round down to 70.
Part C: True or False?
Read each statement. Circle True or False.
1. 33 rounded to the nearest ten is 30.
True False
The ones digit in 33 is 3, which is less than 5, so 33 rounds down to 30.
2. 76 rounded to the nearest ten is 70.
True False
The ones digit in 76 is 6, which is 5 or greater, so 76 actually rounds up to 80, not 70.
3. A number with a ones digit of 4 always rounds down to the nearest ten.
True False
Since 4 is always less than 5, any number with a ones digit of 4 will round down to the nearest ten.