What is Rounding Decimals?

Rounding decimals means changing a decimal number to make it easier to work with. We do this by changing the number to the nearest whole number or to a specified decimal place.

Why Do We Round?

Rounding helps us:

  • Make calculations simpler.
  • Understand numbers better.
  • Estimate answers quickly.

Key Rules for Rounding Decimals

  1. Look at the digit to the right of the place you want to round to.
    • If it’s 5 or more, you round up.
    • If it’s 4 or less, you round down.
  2. Decide where to round:
    • If you want to round to the nearest whole number, look at the first decimal place.
    • If you want to round to one decimal place, look at the second decimal place.

Examples

  1. Rounding to the nearest whole number:
    • 4.7: Look at 7. Since it’s 5 or more, round up to 5.
    • 4.3: Look at 3. Since it’s 4 or less, round down to 4.
  2. Rounding to one decimal place:
    • 3.76: Look at 6. Since it’s 5 or more, round up to 3.8.
    • 2.34: Look at 4. Since it’s 4 or less, round down to 2.3.
  3. Rounding to two decimal places:
    • 5.678: Look at 8. Since it’s 5 or more, round up to 5.68.
    • 1.234: Look at 4. Since it’s 4 or less, round down to 1.23.

Tips and Tricks

  • Use a number line to help you visualise where the number lies.
  • Remember the rhyme: “Four and below, let it go; five and above, give it a shove!”
  • Practice with different numbers to get used to rounding.

Practice Questions

Easy Level (Round to Nearest Whole Number)

  1. Round 2.4
  2. Round 7.8
  3. Round 5.3
  4. Round 9.5
  5. Round 3.2
  6. Round 6.6
  7. Round 1.9
  8. Round 4.4
  9. Round 8.7
  10. Round 0.2

Medium Level (Round to One Decimal Place)

  1. Round 3.75
  2. Round 4.82
  3. Round 6.43
  4. Round 5.88
  5. Round 2.34
  6. Round 9.49
  7. Round 7.15
  8. Round 8.76
  9. Round 1.23
  10. Round 0.67

Hard Level (Round to Two Decimal Places)

  1. Round 3.456
  2. Round 7.891
  3. Round 5.678
  4. Round 2.345
  5. Round 9.999
  6. Round 4.567
  7. Round 1.234
  8. Round 6.789
  9. Round 0.123
  10. Round 8.765

Answers

Easy Level Answers

  1. 2.4 rounds to 2.
  2. 7.8 rounds to 8.
  3. 5.3 rounds to 5.
  4. 9.5 rounds to 10.
  5. 3.2 rounds to 3.
  6. 6.6 rounds to 7.
  7. 1.9 rounds to 2.
  8. 4.4 rounds to 4.
  9. 8.7 rounds to 9.
  10. 0.2 rounds to 0.

Medium Level Answers

  1. 3.75 rounds to 3.8.
  2. 4.82 rounds to 4.8.
  3. 6.43 rounds to 6.4.
  4. 5.88 rounds to 5.9.
  5. 2.34 rounds to 2.3.
  6. 9.49 rounds to 9.5.
  7. 7.15 rounds to 7.2.
  8. 8.76 rounds to 8.8.
  9. 1.23 rounds to 1.2.
  10. 0.67 rounds to 0.7.

Hard Level Answers

  1. 3.456 rounds to 3.46.
  2. 7.891 rounds to 7.89.
  3. 5.678 rounds to 5.68.
  4. 2.345 rounds to 2.35.
  5. 9.999 rounds to 10.00.
  6. 4.567 rounds to 4.57.
  7. 1.234 rounds to 1.23.
  8. 6.789 rounds to 6.79.
  9. 0.123 rounds to 0.12.
  10. 8.765 rounds to 8.77.

Happy rounding, Year 5! Keep practicing, and you’ll get the hang of it!