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:
420 rounded to the nearest hundred is 500.
Corrected: 420 rounded to the nearest hundred is 400 because 2 is less than 5 so we round down.
When rounding 420 to the nearest hundred, look at the tens digit, which is 2. Since 2 is less than 5, you round down to 400.
2. Fix the sentence:
783 rounded to the nearest hundred is 700.
Corrected: 783 rounded to the nearest hundred is 800 because 8 is 5 or greater so we round up.
When rounding 783 to the nearest hundred, look at the tens digit, which is 8. Since 8 is 5 or greater, you round up to 800.
3. Fix the sentence:
250 rounded to the nearest hundred is 200.
Corrected: 250 rounded to the nearest hundred is 300 because when the tens digit is exactly 5 we round up.
The tens digit in 250 is exactly 5, and the rule says to round up when the digit is 5. So 250 rounds up to 300, not down to 200.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. 310 rounded to the nearest hundred is 300.
The tens digit in 310 is 1, which is less than 5, so 310 rounds down to 300.
2. 567 rounded to the nearest hundred is 600.
The tens digit in 567 is 6, which is 5 or greater, so 567 rounds up to 600.
3. 892 rounded to the nearest hundred is 900.
The tens digit in 892 is 9, which is 5 or greater, so 892 rounds up to 900.
4. 135 rounded to the nearest hundred is 100.
The tens digit in 135 is 3, which is less than 5, so 135 rounds down to 100.
Part C: True or False?
Read each statement. Circle True or False.
1. When rounding to the nearest hundred, you look at the tens digit.
True False
To round to the nearest hundred, you check the tens digit to decide whether to round up or down, just like you check the ones digit when rounding to the nearest ten.
2. 620 rounded to the nearest hundred is 700.
True False
The tens digit in 620 is 2, which is less than 5, so 620 rounds down to 600, not up to 700.
3. 850 rounded to the nearest hundred is 900.
True False
The tens digit in 850 is 5, and when the digit is exactly 5, you round up. So 850 rounds up to 900.