Mathematics · Lesson · Class 4–6

Whole Numbers: place value, comparing and rounding

Q: How do you round a number when the last digit is 5?

If the deciding digit is 5 or more, round the digit before it up. Example: 67 rounded to the nearest ten becomes 70, because 7 is 5 or more. If the deciding digit is 4 or less, keep it the same: 62 becomes 60.

Q: Why do we round numbers?

Rounding gives quick, useful estimates. Shops round prices, scientists report measurements to sensible precision, and exams test whether you can estimate — for example, 4,839 ≈ 4,800 to the nearest hundred.

Whole numbers are the counting numbers — 0, 1, 2, 3, 4 and so on, forever. Every digit in a whole number has a place value that tells you how much it is worth. Once you understand place value, comparing numbers (which is bigger?) and rounding numbers (about how much?) become easy.

1. Place value — every digit has an address

Look at the number 4,832. Read it from left to right:

4,832 = 4 thousands + 8 hundreds + 3 tens + 2 ones

= 4,000 + 800 + 30 + 2

Words: “four thousand eight hundred thirty-two”

The same digit changes its worth depending on where it stands. In 555, the first 5 means 500, the middle 5 means 50 and the last 5 means 5 — identical digits, triple the value just by position.

2. Comparing numbers — which is bigger?

Use three symbols: > (greater than), < (less than), = (equal to).

Step 1: count the digits. More digits = bigger number. Example: 1,250 > 999 (1,250 has 4 digits, 999 has 3).

Step 2: same number of digits? Compare from the left, digit by digit. Example: 6,418 vs 6,215 — thousands equal (6), hundreds 4 > 2, so 6,418 > 6,215.

Step 3: the > symbol opens toward the bigger number, like a hungry crocodile mouth 🐊

3. Rounding numbers — about how much?

Rounding replaces a number with a nearby “nicer” number. It is an estimate, not the exact value.

Rule: look at the digit right after the place you are rounding to.

→ If it is 0–4, keep the digit the same and make everything after it 0.

→ If it is 5–9, add 1 to the digit and make everything after it 0.

Example A: 3,472 to the nearest hundred. Tens digit = 7 (5–9), so → 3,500.

Example B: 6,241 to the nearest ten. Ones digit = 1 (0–4), so → 6,240.

Try it yourself

1. In the number 7,309, what is the place value of 3?

2. Which statement is correct?

3. Round 5,683 to the nearest hundred.

Remember 3 things

Place value = position × face value. The digit is worth what its address says.
Compare from the left-most digit; the first bigger digit wins.
Round by looking at the digit to the right of the target place: 5 or more rounds up.

Frequently asked questions

What is place value in simple words?

Place value means the value of a digit depends on where it sits. In 4,832, the 4 is worth 4,000, the 8 is worth 800, the 3 is worth 30 and the 2 is worth 2.

How do you round a number when the last digit is 5?

If the deciding digit is 5 or more, round up: 67 → 70 (nearest ten). If it is 4 or less, keep it: 62 → 60.

Why do we round numbers?

Rounding gives quick, useful estimates — shops, scientists and exams all use it when an exact figure isn't needed.