Rounding always works the same way. Only the place you round to changes.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Three steps
Find the two numbers either side at that place. Find halfway. See which side you are on.
An example
4,672 to the nearest hundred sits between 4,600 and 4,700. Halfway is 4,650, and 4,672 is past it.
Different places, different answers
4,672 rounds to 4,670 to the nearest ten, 4,700 to the nearest hundred, and 5,000 to the nearest thousand.
Step 2: Try It Yourself
Tap and try it out.
672 sits past halfway, so it rounds to 700.
Step 3: In Real Life
A stadium crowd
A stadium counts 47,312 fans. The news says about 47,000. That is rounding to the thousand. A report rounds to the place people can picture.
Step 4: Watch an Example
One step at a time.
Watch Leo Round the Same Number Three Ways
Leo rounds 4,672 to the nearest ten, hundred, and thousand.
- Step 1
To the nearest ten: between 4,670 and 4,680, halfway is 4,675, so it rounds down.
Step 5: Your Turn
Practice makes it stick.
The Crowd
Problem 1 of 2
Round 3,482 to the nearest hundred.
To the Thousand
Problem 2 of 2
Round 3,482 to the nearest thousand.
Round to the Place Asked
1 of 4
Round 2,748 to the nearest ten.
2 of 4
Round 2,748 to the nearest hundred.
3 of 4
Round 2,748 to the nearest thousand.
4 of 4
Round 15,600 to the nearest thousand.
Land on It
Build it, then check.
Put the marker on 672.
Step 6: Quick Check
Show what you know.
Question 1 of 2
Round 6,349 to the nearest hundred.
Question 2 of 2
Does one number always round to the same answer?
What You Learned
- Rounding works the same way at any place.
- Find the two neighbors, find halfway, pick a side.
- The same number rounds differently at different places.
For the grown-up
This lesson is where the child rounds a multi-digit number to any named place. Each place is ten times the one to its right, and that single rule generates the whole system all the way to a million and, later, all the way down past the decimal point.
Watch for large numbers read digit by digit. "Four hundred and seven thousand" is a structure; "four zero seven" is a phone number.
Have them say the number aloud before working with it. Most errors with big numbers are reading errors that the arithmetic then faithfully preserves.
One method, any place — Rounding always asks the same question: which of the two nearest landmarks is this number closer to? To round 47,382 to the nearest thousand, the landmarks are 47,000 and 48,000. 47,382 is below the halfway point of 47,500, so the answer is 47,000.
The deciding digit — Look at the digit immediately to the right of the place you are rounding to. If it is 5 or more, round up; if it is 4 or less, round down. Everything further right is already accounted for by that digit — this is why you do not need to inspect the whole tail.
Everything to the right becomes zero — Rounding 47,382 to the nearest thousand gives 47,000, not 47. The zeros hold the places open so the number keeps its size. Dropping them changes the answer by a factor of a thousand — a mistake that is easy to make and very easy to spot if you check.
When rounding up cascades — Round 39,700 to the nearest thousand and the 39 becomes 40: the answer is 40,000. Rounding up can fill a column and push a bundle further left, just as carrying does. Expect it whenever the digits before the deciding one are 9s.
Look one place to the right — Round 47,382 to the nearest thousand. It lies between 47,000 and 48,000. Look at the hundreds digit: 3. Below 5, so it is nearer the lower one. 47,000 Rounding to the nearest hundred instead? Look at the tens: 8. Round up: 47,400.