Adding & Subtracting Decimals — Free KS3 Worksheet
A free, printable KS3 worksheet on adding and subtracting decimals using the column method, with a full worked answer key. 16 questions graded easy to hard for Years 7, 8 and 9, including word problems.
Adding and subtracting decimals is ordinary column arithmetic with one extra rule: line up the decimal points, not the ends of the numbers. Once the points are in a column, every digit is above one of the same size, and the sum behaves exactly as it does with whole numbers.
What is on the sheet
Pairs with the same number of decimal places first, where lining up happens naturally. Then pairs with different lengths, which is where the topic actually lives, and where filling the gaps with zeros makes everything easier. Subtraction with borrowing across the point follows. Weight, volume and money questions close the sheet, because that is where decimals turn up outside a maths lesson and where a misplaced point is obvious.
Marking it
The adding and subtracting decimals lesson sets every example out in columns first, which is the habit worth building.
Keep going
More decimals & rounding practice
Ordering Decimals & Place Value — Free KS3 Worksheet
A free, printable KS3 worksheet on ordering and comparing decimals using place value, with a full worked answer key. 16 questions graded easy to hard for Years 7, 8 and 9, including word problems.
Multiplying & Dividing Decimals — Free KS3 Worksheet
A free, printable KS3 worksheet on multiplying and dividing decimals, with a full worked answer key. 16 questions graded easy to hard for Years 7, 8 and 9, including word problems.
Rounding Decimals to Decimal Places — Free KS3 Worksheet
A free, printable KS3 worksheet on rounding decimals to 1, 2 and 3 decimal places, with a full worked answer key. 16 questions graded easy to hard for Years 7, 8 and 9 — including the carry and trailing-zero traps.
Want all 4 decimals & rounding worksheets at once?
One PDF, 64 questions, every answer key included, in teaching order. Every sheet in it is free on its own page too. The pack just saves you collecting them one at a time.