How do I add decimal numbers?

Adding decimal numbers is done exactly the same as normal numbers: the column method.

When you have 2 decimal numbers to add together the most important thing is to line up the decimal points (dots) so that they're all above each other. You should now have 2 numbers on top of each other to add together. If you have any gaps then quickly draw a 0 to fill it.

After this, start on the right hand side of the column and add together the numbers which are on top of each other. If the answer is less than 10 then write it below the numbers you just added together. If the number is above 10 then write down the last number: for example if your answer is 15 then write down 5, if your answer is 47 then write down 7, and if your answer is 22 then write down 2. The tens carries over to the next column of numbers (the column to the left of the one you just added together).

Keep doing this until you get to the far left of the column. If you've lined up the decimal point then you shouldnt have to worry about it whilst you do all the adding. 

Finally, add a decimal point into your answer exactly below the others in your column equation. 

Maddie S. 13 plus  Maths tutor, GCSE Maths tutor, 11 Plus Maths tutor

5 months ago

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