Decimals Made Easy!

Year 5 – 11+ Maths

1️⃣ Adding and Subtracting Decimals

✅ Always line up the decimal points before you calculate.

Example 1: Addition

1.350

+ 0.125

-------

1.475

Example 2: Subtraction

34.78

- 4.30

------

30.48

Add zeros if needed to keep columns neat.

2️⃣ Multiplying Decimals

✅ Put the number with the most digits at the top

❌ It does not have to be the biggest number

✅ Do NOT line up decimal points

✅ Multiply first, then add the decimal at the end

Example: 4.5 × 0.328

Step 1: Write the number with more digits on top

328

× 45

-----

Step 2: Multiply as whole numbers

328

× 45

-----

1640

13120

-----

14760

Step 3: Count decimal places

• 0.328 has 3 decimal places

• 4.5 has 1 decimal place

• Total = 4 decimal places

Step 4: Put the decimal in the answer

1.4760

✔ Final answer: 1.476

3️⃣ Comparing the Size of Decimals

✅ Make sure all numbers have the same number of decimal places

This makes comparing much easier.

Example: Order these decimals

0.1, 0.24, 0.011

Rewrite them:

• 0.100

• 0.240

• 0.011

Now compare easily.

�� Biggest to smallest:

0.240, 0.100, 0.011

4️⃣ Finding the Halfway Point Between Two Decimals

✅ Add the two numbers

✅ Divide the total by 2

Example: Halfway between 1.2 and 5.6

Step 1: Add

1.2 + 5.6 = 6.8

Step 2: Divide by 2

6.8 ÷ 2 = 3.4

✔ Halfway point = 3.4

Top Tips ⭐

• Line up decimal points for adding and subtracting

• Ignore decimals when multiplying, then add them at the end

• Add zeros to help with comparing decimals

• Work neatly and double-check your answers