SEAGReady
NumberP6 level20 questions in the full course

Add and Subtract DecimalsSEAG Practice Questions

Adding and subtracting decimal numbers using column method with aligned decimal points.

Where your child meets this in real life: Adding up prices, calculating change with pounds and pence, or totalling measurements

What your child needs to know

SEAGReady breaks add and subtract decimals into 3 steps, taught in order so each skill builds on the last.

  1. 1

    Same Decimal Places, No Carrying

    Add and subtract decimal numbers with the same number of decimal places without requiring carrying or borrowing

  2. 2

    Same Decimal Places, With Carrying

    Add and subtract decimal numbers with the same number of decimal places when carrying or borrowing is required

  3. 3

    Different Decimal Places

    Add and subtract decimal numbers with different numbers of decimal places by matching place values through zeros

Try these SEAG-style questions

Three free sample questions from our add and subtract decimals course. Every question comes with a full explanation, and hints that guide without giving the answer away.

Question 1Confidence builder

Poppy bought a ruler for £1.24 and an eraser for £0.53 at the school shop. How much did she spend altogether?

Answer choices for question 1
Question 2Confidence builder

Katie walked 3.8 km in the morning and 1.6 km in the afternoon. How far did she walk altogether?

Answer choices for question 2
Question 3Confidence builder

Ella has £5 pocket money. She buys a magazine for £2.35. How much money does she have left?

A money column layout writes £5 as £5.00 above £2.35, aligned by decimal place, without showing any regrouping or the difference.
Answer choices for question 3

Try the lesson: Same Decimal Places, No Carrying

This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.

Ella bought a notebook for £2.35 and a pen for £1.42 at the school shop.

How much did she spend altogether?

2.35 + 1.42

Line up the decimal points
1

Write the numbers in columns with the decimal points directly above each other

Step 1 of 4

Prefer to read? See every step written out

Ella bought a notebook for £2.35 and a pen for £1.42 at the school shop.

How much did she spend altogether?

  1. 1

    Line up the decimal points

    • Write the numbers in columns with the decimal points directly above each other
  2. 2

    Add each column from right to left

    • Hundredths: 5 + 2 = 75 + 2 = 7
    • Tenths: 3 + 4 = 73 + 4 = 7
    • Ones: 2 + 1 = 3, then place the decimal point2 + 1 = 3

Ella spent £3.77 altogether.

The key insight: Adding decimals works just like whole numbers - just keep those decimal points lined up!

Common mix-up: 2.35 + 1.42 = 377 (forgetting the decimal point). The decimal point in the answer must line up with the decimal points above it.

Mistakes to watch for

These are the misconceptions we see most often in add and subtract decimals, including the ones our practice questions are specifically designed to catch.

  • Not lining up decimal points in columns
  • Forgetting to include the decimal point in the answer
  • Treating digits before and after the point separately

Build these skills first

Struggling with add and subtract decimals? The real gap is often in one of these earlier topics.

Decimal Place ValueColumn AdditionColumn Subtraction

More number practice

Read & Write Whole NumbersIdentify Place Value of a DigitCompare Two Whole NumbersOrder a Set of Whole NumbersAddition Facts to 20Subtraction Facts Within 20
20 questions on this topic alone

Master add and subtract decimals and everything it unlocks

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.

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