Decimal Subtraction

Subtracting decimals follows the same column method as subtracting whole numbers. The key rule: align the decimal points before you begin.

The Golden Rule – Align the Decimal Point

8.4 − 3.57 → write as 8.40 − 3.57, align points, then subtract

Padding with Zeros

Add trailing zeros so both numbers have the same number of decimal places.

Original	Padded
7.5 − 2.38	7.50 − 2.38
5 − 1.234	5.000 − 1.234

Try It: 20.4 − 7.65

Decimal point alignment

Padding zero

Borrowed digit

Result digit

Click Step 1 or Auto Play to begin!

20.4 − 7.65 = 12.75
Pad 20.4 to 20.40. The ones digit is 0, so borrowing has to reach back through the tens column first — the tricky case of borrowing through a zero.

Worked Examples

Easy

9.7 − 4.3: ones 9−4=5, tenths 7−3=4. Answer: 5.4

Medium – With Borrowing

6.32 − 2.87: hundredths 2−7 borrow; 12−7=5. Tenths 2−8 borrow; 12−8=4 (adjusted). Ones 5−2=3. Answer: 3.45

Advanced

12.5 − 8.375: pad 12.500 − 8.375. Work right to left with borrowing. Answer: 4.125

Real-Life Applications

Calculating change: £10 − £3.47 = £6.53
Comparing measurements: 2.85 m − 1.6 m = 1.25 m
Tracking weight loss or gain in health.

Key Takeaways

Always align decimal points before subtracting.
Pad with trailing zeros where needed.
Borrowing works exactly as with whole numbers.
The decimal point in the answer sits directly below those in the calculation.

Practice: Subtract These Decimals

Two decimals with different numbers of decimal places are shown below. If you get it wrong (or leave it blank), we'll align the decimal points together.

Calculate the difference.