Adding or subtracting decimal numbers is same as any adding or taking away whole numbers. The only difference is that you have another column (after the ‘ones’ column). So, first add your 100s, next your 10s, then your ones, and finally your decimals.  Tips: Add the whole numbers first, then add the decimal parts. For example, 1.5 + 3.6 - 2.4 = (1 + 3 - 2) + (0.5 + 0.6 - 0.4) = 2 + 0.7 = 2.7 With numbers less than 1,000, add the hundreds first, then the tens and then the ones. For example: 120 + 360 + 25 + 8 = (100 + 300) + (20 + 60 + 20) + (5 + 8) = 400 + 100 + 13 = 513 Related... Show more

Adding or subtracting decimal numbers is same as any adding or taking away whole numbers. The only difference is that you have another column (after the ‘ones’ column).

So, first add your 100s, next your 10s, then your ones, and finally your decimals. 

Tips:

1. Add the whole numbers first, then add the decimal parts. For example, 1.5 + 3.6 - 2.4 = (1 + 3 - 2) + (0.5 + 0.6 - 0.4) = 2 + 0.7 = 2.7
2. With numbers less than 1,000, add the hundreds first, then the tens and then the ones. For example: 120 + 360 + 25 + 8 = (100 + 300) + (20 + 60 + 20) + (5 + 8) = 400 + 100 + 13 = 513

Related Tests:

11 Plus (11+) Maths Practice Test: Addition and Subtraction (Easy) 

11 Plus (11+) Maths Practice Test: Addition and Subtraction (Medium) 

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