This deep dive covers Method: Adding and Subtracting Decimals within Integers & Decimals for GCSE Mathematics. Revise Integers & Decimals in Number for GCSE Mathematics with 14 exam-style questions and 22 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 4 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Method: Adding and Subtracting Decimals
1
Write numbers vertically, aligning decimal points
2
Fill empty places with zeros (e.g., 12.3 → 12.30)
3
Add/subtract as normal, column by column
4
Place decimal point in answer directly below others
Practice questions for Integers & Decimals
What is the value of the digit 4 in the number 12.345?
Explain how to multiply two decimal numbers without a calculator.
Quick recall flashcards
What is a decimal?
A number with a decimal point showing parts of a whole. The digits after the point represent tenths, hundredths, thousandths, etc.
Money calculation
£4.25 + £12.30 + £8.75
Line up decimals:
4.25
12.30
+ 8.75
------
25.30
Answer: £25.30