Rounding Worksheets to the Nearest 10 and 100 - Complete Guide

Master rounding worksheets to the nearest 10 and 100 with these 5 detailed exercises and visual explanations.

Solution: Exercises 1 to 3
1 Rounding to the nearest 10
Exercise 1
Round 74 to the nearest 10.
Definition:

Rounding to the nearest 10: Finding the closest multiple of 10 to a given number.

Rounding method:
  1. Look at the digit in the ones place (rightmost digit)
  2. If the ones digit is 0, 1, 2, 3, or 4 → round down
  3. If the ones digit is 5, 6, 7, 8, or 9 → round up
  4. Change the ones digit to 0 and keep other digits the same
Number
74
Ones digit
4
Result
70
Step 1: Identify the ones digit

In 74, the ones digit is 4.

Step 2: Apply the rounding rule

Since 4 ≤ 4, we round down to the previous multiple of 10.

Step 3: Change the ones digit to 0

Keep the tens digit (7) and change the ones digit to 0: 70.

60
65
70
75
80
85
90
95
100
74
70
74 rounded to the nearest 10 is 70
Final answer:

74 rounded to the nearest 10 is 70

Applied rules:

• Rounding Rule: If ones digit ≥ 5, round up; if ones digit ≤ 4, round down

• Place Value: Focus on the ones place for rounding to nearest 10

• Multiples of 10: Numbers ending in 0 (10, 20, 30, 40, etc.)

2 Rounding to the nearest 100
Exercise 2
Round 467 to the nearest 100.
Definition:

Rounding to the nearest 100: Finding the closest multiple of 100 to a given number.

Number
467
Tens digit
6
Result
500
Step 1: Identify the tens digit

In 467, the tens digit is 6 (the digit in the tens place).

Step 2: Apply the rounding rule

Since 6 ≥ 5, we round up to the next multiple of 100.

Step 3: Change the tens and ones digits to 0

Keep the hundreds digit (4) and change the tens and ones digits to 0, then add 1 to hundreds: 400 + 100 = 500.

300
350
400
450
500
550
467
500
467 rounded to the nearest 100 is 500
Final answer:

467 rounded to the nearest 100 is 500

Applied rules:

• Rounding Rule: If tens digit ≥ 5, round up; if tens digit ≤ 4, round down

• Place Value: Focus on the tens place for rounding to nearest 100

• Multiples of 100: Numbers ending in 00 (100, 200, 300, 400, etc.)

3 Mixed rounding practice
Exercise 3
Round 384 to the nearest 10 and to the nearest 100.
Definition:

Mixed rounding practice: Applying different rounding rules to the same number.

Number
384
To nearest 10
380
To nearest 100
400
Step 1: Round to nearest 10

Look at ones digit: 4. Since 4 ≤ 4, round down to 380.

Step 2: Round to nearest 100

Look at tens digit: 8. Since 8 ≥ 5, round up to 400.

Step 3: Compare results

384 → 380 (nearest 10) and 384 → 400 (nearest 100)

Rounding Target Target Digit Rule Applied Result
To nearest 10 Ones digit (4) 4 ≤ 4 → Round down 380
To nearest 100 Tens digit (8) 8 ≥ 5 → Round up 400
384 rounded to nearest 10 is 380
384 rounded to nearest 100 is 400
Final answer:

384 rounded to nearest 10 is 380
384 rounded to nearest 100 is 400

Applied rules:

• For nearest 10: Look at ones digit (4), since 4 ≤ 4, round down to 380

• For nearest 100: Look at tens digit (8), since 8 ≥ 5, round up to 400

• Different results: Same number can have different rounded values depending on place value

Rounding Rules, Methods, and Practice Guide
Detailed Summary

Definitions:

Rounding: Making a number simpler while keeping its value close to what it was. Rounding is often used to make numbers easier to work with or to estimate.

Multiple of 10: A number that can be divided evenly by 10. These numbers end in 0: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, etc.

Multiple of 100: A number that can be divided evenly by 100. These numbers end in 00: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, etc.

Ones Place: The rightmost digit in a whole number, representing how many ones are in the number.

Tens Place: The second digit from the right in a whole number, representing how many tens are in the number.

Core Rules:

• If rounding to nearest 10: If ones digit ≥ 5, round up; if ones digit ≤ 4, round down

• If rounding to nearest 100: If tens digit ≥ 5, round up; if tens digit ≤ 4, round down

• When rounding up, add 1 to the target place value

Methods and Procedures:

1. Look at the number to be rounded

2. Determine whether rounding to nearest 10 or 100

3. Identify the target digit (ones for nearest 10, tens for nearest 100)

4. Apply the rounding rule based on the target digit

5. Change lower place values to 0

6. If rounding up, add 1 to the target place value

Examples:

Round to nearest 10: 42 → 40 (ones digit 2 ≤ 4)

Round to nearest 10: 57 → 60 (ones digit 7 ≥ 5)

Round to nearest 100: 324 → 300 (tens digit 2 ≤ 4)

Round to nearest 100: 687 → 700 (tens digit 8 ≥ 5)

Tips and Tricks:

• "5 or more, raise the score; 4 or less, let it rest" - memory trick for rounding

• Always focus on the target digit (ones for nearest 10, tens for nearest 100)

• Circle or underline the target digit to avoid confusion

• Use number lines to visualize where the number falls between multiples

Key Notes to Remember:

• Rounding 5 always goes up (this is a standard mathematical convention)

• When rounding to nearest 10, only the ones digit matters

• When rounding to nearest 100, only the tens digit matters

To nearest 10:
Ones digit ≥ 5 → Round UP
Ones digit ≤ 4 → Round DOWN
Rounding Rule for Nearest 10
To nearest 100:
Tens digit ≥ 5 → Round UP
Tens digit ≤ 4 → Round DOWN
Rounding Rule for Nearest 100
10
20
30
40
50
60
70
80
90
100
Rule 1
Round to nearest 10
Focus on ones digit
Rule 2
Round to nearest 100
Focus on tens digit
Rule 3
Round UP
Digit ≥ 5
Key definitions:

Rounding: Making a number simpler but keeping its value close to what it was

Multiple of 10: Numbers ending in 0 (10, 20, 30, 40, etc.)

Multiple of 100: Numbers ending in 00 (100, 200, 300, 400, etc.)

Ones Place: The rightmost digit in a number

Tens Place: The second digit from the right in a number

Complete methodology:
  1. Identify the number: Look at the whole number to be rounded
  2. Determine rounding target: Decide if rounding to nearest 10 or 100
  3. Locate the target digit: For nearest 10, find ones digit; for nearest 100, find tens digit
  4. Apply the rule: If target digit ≥ 5, round up; if target digit ≤ 4, round down
  5. Adjust the number: Change lower place values to 0 and adjust target place if needed
Tip 1: Think of rounding as finding the closest "friend" that ends in 0 (for 10) or 00 (for 100).
Tip 2: Use a number line to visualize which multiple of 10 or 100 is closer.
Tip 3: Remember: 5 is the "tie-breaker" - when the digit is exactly 5, we round up.
Tip 4: When rounding up, add 1 to the target place value.
Common errors: Looking at wrong place value, forgetting to change digits to 0, misapplying the 5 rule.
Memory aid: "5 or more, raise the score; 4 or less, let it rest."
Key rules to remember:

• For nearest 10: Look at ones digit, round up if ≥ 5, down if ≤ 4

• For nearest 100: Look at tens digit, round up if ≥ 5, down if ≤ 4

• Change digits: When rounding, make lower place values 0

• Add 1: When rounding up, increase the target place value by 1

Solution: Exercises 4 to 5
4 Rounding to the nearest 10
Exercise 4
Round 829 to the nearest 10.
Definition:

Rounding to the nearest 10: Finding the closest multiple of 10 to a given number.

Number
829
Ones digit
9
Result
830
Step 1: Identify the ones digit

In 829, the ones digit is 9 (the rightmost digit).

Step 2: Apply the rounding rule

Since 9 ≥ 5, we round up to the next multiple of 10.

Step 3: Change the ones digit to 0

Keep the tens and hundreds digits (82) and change the ones digit to 0, then add 1 to tens: 820 + 10 = 830.

810
815
820
825
830
835
829
830
829 rounded to the nearest 10 is 830
Final answer:

829 rounded to the nearest 10 is 830

Applied rules:

• Rounding Rule: If ones digit ≥ 5, round up; if ones digit ≤ 4, round down

• Place Value: Focus on the ones place for rounding to nearest 10

• Multiples of 10: Numbers ending in 0 (10, 20, 30, 40, etc.)

5 Mixed rounding practice
Exercise 5
Round 651 to the nearest 10 and to the nearest 100.
Definition:

Mixed rounding practice: Applying different rounding rules to the same number.

Number
651
To nearest 10
650
To nearest 100
700
Step 1: Round to nearest 10

Look at ones digit: 1. Since 1 ≤ 4, round down to 650.

Step 2: Round to nearest 100

Look at tens digit: 5. Since 5 ≥ 5, round up to 700.

Step 3: Compare results

651 → 650 (nearest 10) and 651 → 700 (nearest 100)

Rounding Target Target Digit Rule Applied Result
To nearest 10 Ones digit (1) 1 ≤ 4 → Round down 650
To nearest 100 Tens digit (5) 5 ≥ 5 → Round up 700
651 rounded to nearest 10 is 650
651 rounded to nearest 100 is 700
Final answer:

651 rounded to nearest 10 is 650
651 rounded to nearest 100 is 700

Applied rules:

• For nearest 10: Look at ones digit (1), since 1 ≤ 4, round down to 650

• For nearest 100: Look at tens digit (5), since 5 ≥ 5, round up to 700

• Different results: Same number can have different rounded values depending on place value

Questions & Answers

Question: Why do we round 5 up instead of down? It seems like it should go to the smaller number.

Answer: Great question! We round 5 up because it's exactly in the middle between two multiples, so we need a consistent rule. Here's why:

  • When we have a number like 35, it's equally close to 30 and 40
  • Instead of having a separate rule for 5, mathematicians decided to always round up when the target digit is 5 or more
  • This creates a consistent pattern: 0,1,2,3,4 round down; 5,6,7,8,9 round up
  • It also helps avoid bias in statistics - if we always rounded 5 down, we'd consistently underestimate

Think of it as a tie-breaker: when there's a tie, we break it by going up!

Question: My child gets confused about which digit to look at when rounding to nearest 10 vs nearest 100. Any tips to help them remember?

Answer: Here are some helpful strategies to teach your child:

  • Count backwards: For rounding to nearest 10, count back 1 place (ones digit); for nearest 100, count back 2 places (tens digit)
  • Circle the digit: Have your child circle the target digit before rounding
  • Memory phrase: "Look at the one behind the one you want" - if rounding to 10s, look at the ones place
  • Visual aids: Draw arrows pointing to the target digit

Practice with the same number rounded to different place values to reinforce the concept!

Question: What happens when I have to round 99 to the nearest 10? The 9 has to go up to 10!

Answer: Excellent observation! When rounding 99 to the nearest 10, here's what happens:

  • Look at the ones digit: 9
  • Since 9 ≥ 5, we round up
  • The ones digit becomes 0, and we add 1 to the tens place
  • The tens place is 9, so adding 1 makes it 10
  • This means 99 rounds up to 100

This is called regrouping - when rounding causes a digit to become 10, it moves to the next place value. It's perfectly normal!