Rounding asks which mark a number is closer to. It is a question about distance.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Find the two neighbors first
To round 3.47 to tenths, notice it sits between 3.4 and 3.5.
Then decide
3.47 is past halfway, so it is nearer 3.5.
Exactly halfway
A number landing exactly on the midpoint rounds up. That is a convention, agreed so everyone matches.
Step 2: Try It Yourself
Tap and try it out.
37
37 sits past halfway, so it rounds to 40.
Step 3: In Real Life
The gas pump
The pump shows 12.468 gallons. The receipt says 12.47. Rounded to the nearest hundredth, because nobody pays for a thousandth of a gallon.
Step 4: Watch an Example
One step at a time.
Watch Ana Round 3.47
Ana rounds 3.47 to the nearest tenth.
- Step 1
She finds the neighbours: 3.4 and 3.5.
Step 5: Your Turn
Practice makes it stick.
The Measurement
Problem 1 of 2
Round 2.83 to the nearest tenth. What is the tenths digit?
The Price
Problem 2 of 2
Round 6.5 to the nearest whole number.
Round It
1 of 4
Round 4.62 to the nearest whole number.
2 of 4
Round 4.28 to the nearest whole number.
3 of 4
Round 9.5 to the nearest whole number.
4 of 4
Round 12.49 to the nearest whole number.
Land on It
Build it, then check.
Put the marker on 37.
Step 6: Quick Check
Show what you know.
Question 1 of 2
Round 7.63 to the nearest whole number.
Question 2 of 2
What question does rounding really ask?
What You Learned
- Rounding asks which mark is nearer.
- Find the two neighbors, then the midpoint.
- Exactly halfway rounds up by agreement.
For the grown-up
This lesson is where the child rounds decimals to any place using a number line. The pattern that built whole numbers continues to the right of the decimal point without changing. Each place is a tenth of the one before, which is the same rule read the other way.
Watch for the decimal point being treated as a separator between two whole numbers. It is a marker for where the ones place ends, nothing more.
Say the place names aloud: three and four tenths, not three point four. The words carry the structure that the notation hides.
Same question as always — Rounding 3.472 to the nearest hundredth means asking whether it is closer to 3.47 or 3.48. The halfway point is 3.475, and 3.472 is below it, so the answer is 3.47. The number line reasoning is identical to whole-number rounding.
The deciding digit — Look at the digit immediately right of the place you are rounding to. Here that is the 2 in the thousandths, which is below 5, so round down. Digits further right cannot change the outcome — 3.4749999 still rounds to 3.47.
Digits to the right are dropped, not zeroed — Rounding 3.472 to hundredths gives 3.47, not 3.470 — though writing 3.470 is not wrong, just unnecessary. This differs from whole numbers, where the places to the right must be filled with zeros to preserve size. Decimal places to the right of the last digit contribute nothing.
Why rounding decimals matters — Money rounds to hundredths, measurements round to whatever the instrument can resolve, and calculators produce more digits than any real measurement justifies. Reporting 3.4718294 meters when your ruler reads to centimeters claims a precision you do not have.
Same rule, past the point — Round 3.457 to the nearest hundredth. It lies between 3.45 and 3.46. Look one place right: the thousandths digit is 7. Five or more, so go up. 3.46 Exactly the rule you used for whole numbers.