Rounding Whole Numbers

Rules for Rounding

1. Find the rounding place (the digit you're rounding to)
2. Look at the digit one place to the right
3. If that digit is 5 or more, round up
4. If that digit is 4 or less, round down (keep the same)
5. Change all digits to the right of the rounding place to 0

Examples

Round 3,742 to the nearest hundred:

• Hundreds digit: 7
• Digit to the right: 4 (less than 5)
• Round down: 3,700 ✅

Round 8,561 to the nearest thousand:

• Thousands digit: 8
• Digit to the right: 5 (5 or more)
• Round up: 9,000 ✅

Round 45,283 to the nearest ten thousand:

• Ten thousands digit: 4
• Digit to the right: 5 (5 or more)
• Round up: 50,000 ✅

Why We Round

Rounding helps us estimate answers quickly:

• About how many students are in the school?
• Approximately how much will these items cost?

Estimation with Rounding

To estimate $3,847 + 2,156$:

• Round: $3,800 + 2,200 = 6,000$ (to nearest hundred)
• Or: $4,000 + 2,000 = 6,000$ (to nearest thousand)

Tip: The actual answer is 6,003. Our estimate was very close!