Multiplying a decimal number by a whole number, understanding how to place the decimal point in the answer.
Where your child meets this in real life: Calculating costs (e.g., 4 × £2.75), or scaling measurements
SEAGReady breaks multiply decimals by whole numbers into 3 steps, taught in order so each skill builds on the last.
Multiply a decimal number with one decimal place by a single-digit whole number (e.g., 3 × 1.5 = 4.5)
Multiply a decimal number with two decimal places by a single-digit whole number (e.g., 4 × 2.75 = 11)
Multiply any decimal number by a two-digit whole number using short multiplication (e.g., 15 × 2.4 = 36.0)
Three free sample questions from our multiply decimals by whole numbers course. Every question comes with a full explanation, and hints that guide without giving the answer away.
Ciara is buying ribbon for a craft project. Each metre costs £1.4. She needs 3 metres. How much will the ribbon cost?
Answer: A. £4.20
Multiply as whole numbers: 3 x 14 = 42 1.4 has one decimal place, so the answer needs one decimal place. 42 becomes 4.2 The ribbon costs £4.20.
Stuck? Start here: She needs 3 metres, and each metre costs £1.4. What operation do you need?
Roisin buys 4 bottles of juice. Each bottle costs £1.25. What is the total cost?
Answer: A. £5.00
Multiply as whole numbers: 4 x 125 = 500 1.25 has two decimal places, so the answer needs two decimal places. 500 becomes 5.00 The total cost is £5.00.
Stuck? Start here: You need to find the cost of 4 bottles at £1.25 each.
A school orders 12 packs of coloured pencils. Each pack costs £2.5. What is the total cost?
Answer: A. £30.00
Multiply as whole numbers: 12 x 25 = 300 2.5 has one decimal place, so the answer needs one decimal place. 300 becomes 30.0 The total cost is £30.00.
Stuck? Start here: The school needs 12 packs at £2.5 each. What operation gives the total?
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
Ciara is buying ribbon for a craft project. Each metre costs £1.4 and she needs 3 metres.
How much will the ribbon cost?
3 × 1.4
Step 1 of 4
Ciara is buying ribbon for a craft project. Each metre costs £1.4 and she needs 3 metres.
How much will the ribbon cost?
The ribbon will cost £4.20.
The key insight: The answer has the same number of decimal places as the decimal you started with!
Watch out: 3 × 1.4 = 42. Forgetting to put the decimal point back gives an answer 10 times too big.
These are the misconceptions we see most often in multiply decimals by whole numbers, including the ones our practice questions are specifically designed to catch.
Struggling with multiply decimals by whole numbers? The real gap is often in one of these earlier topics.
SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.