If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

### Course: Class 6 (Old)>Unit 6

Lesson 5: Subtraction of decimals

# Subtracting decimals: 9.005 - 3.6

Subtracting decimals is simple when you line up the decimal points and fill in missing zeros. Regroup when needed by borrowing from the whole number and adding to the tenths place. Mastering this skill helps with everyday calculations and improves overall math understanding. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• Who invented decimals and fractions???
• The earliest recorded use of place value (writing numbers in a line to represent larger numbers) is from the ancient Babylonians around 1800 BC. However, they didn't have a decimal point, or a concept for zero yet. They just had to write the numbers out and determine how large it was based on context.

Bonus fact: The Babylonians used a base 60 numeral system, which is where we get our measurements of time from (60 seconds to a minute, 60 minutes to an hour)
• Why do you have to line up the decimals when you add or subtract?
• If you don't line them up, you may add ones to tenths, tenths to hundredths, etc. and get wrong answers. Lining them up helps you add or subtract all the proper places and get a correct answer.
• How do you borrow from nothing?.
• go to the next place up, but if you cant go up, you made a mistake and ordered your question wrong or you have to subtract it negatively
• can someone explain this broadly because i do not get it
• why does this exist
• idk man
• this is easy
• when your working with fractions if you get a number like 4.8 + 6.78 the .8 is basically 80 so it would be

4.80
6. 78
• yes you can do that if it makes it easier
• hola so dora
• why does this exist
• this is so easy u just carry the 4