Lesson: Number Rounding

Rounding is a way to simplify numbers by changing them to a nearby, easier number. We round numbers to the nearest ten, hundred, or thousand to make them easier to work with. In this lesson, we’ll learn how to round numbers and when to round up or down.

Rounding to the Nearest Ten

When rounding to the nearest ten, look at the ones place (the last digit):

  • If the ones place is 5 or more, round up.
  • If the ones place is 4 or less, round down.
  • Example: Round 67 to the nearest ten.
    • The ones place is 7 (which is 5 or more), so round up.
    • 67 rounds to 70.
  • Example: Round 43 to the nearest ten.
    • The ones place is 3 (which is 4 or less), so round down.
    • 43 rounds to 40.

Rounding to the Nearest Hundred

When rounding to the nearest hundred, look at the tens place:

  • If the tens place is 5 or more, round up.
  • If the tens place is 4 or less, round down.
  • Example: Round 362 to the nearest hundred.
    • The tens place is 6 (which is 5 or more), so round up.
    • 362 rounds to 400.
  • Example: Round 248 to the nearest hundred.
    • The tens place is 4 (which is 4 or less), so round down.
    • 248 rounds to 200.

Rounding to the Nearest Thousand

When rounding to the nearest thousand, look at the hundreds place:

  • If the hundreds place is 5 or more, round up.
  • If the hundreds place is 4 or less, round down.
  • Example: Round 5,724 to the nearest thousand.
    • The hundreds place is 7 (which is 5 or more), so round up.
    • 5,724 rounds to 6,000.
  • Example: Round 3,421 to the nearest thousand.
    • The hundreds place is 4 (which is 4 or less), so round down.
    • 3,421 rounds to 3,000.

Mixed Rounding – Ten and Hundred

Sometimes, we may need to round numbers to the nearest ten or the nearest hundred in the same activity. Remember the rules for rounding based on the place you are rounding to.

  • Example: Round 563 to the nearest ten and hundred.
    • Nearest ten: The ones place is 3, so round down to 560.
    • Nearest hundred: The tens place is 6, so round up to 600.

Mixed Rounding – Ten, Hundred, and Thousand

You might need to round numbers to the nearest ten, hundred, or thousand. Always check which place you’re asked to round to, and follow the same rules.

  • Example: Round 4,892 to the nearest ten, hundred, and thousand.
    • Nearest ten: The ones place is 2, so round down to 4,890.
    • Nearest hundred: The tens place is 9, so round up to 4,900.
    • Nearest thousand: The hundreds place is 8, so round up to 5,000.