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: Get ready for 3rd grade>Unit 1

Lesson 4: Subtract within 100

# Subtracting with regrouping (borrowing)

Sal subtracts 25 from 83 by thinking about tens and ones.

## Want to join the conversation?

• Does regrouping also apply to subtracting 3- or 4-digit numbers?
• Yes it does! :) It is the same as subtracting two digits, except there are more numbers.
• How do you solve 48-77=? i always get -31 as answer though it should be -29
• What you can do is reorder them, then subtract them like normal, then 'flip' the answer.
`77-48 = 29`
then put a minus on the `29` to make it `-29` and there's your answer!
By the way, I'm not too sure about this way, but try it and see if it works for you!
• So regrouping and borrowing are the same thing?
• Yes they are the same thing.
• Can we borrow if we have an equation like this? 367
-635 = ?
• No since you are taking away more then what you have. In this case subtract 635-367 and make the answer negative. The answer is = -268. Negative means your answer is less than zero.
• Is there a video for subtracting a bigger number from a smaller number? I need a little help with my homework...
• Hi Miraculous Ladybug,
When subtracting a bigger number from a smaller number, something like this should be seen:

5-7 = ?

When a bigger number is subtracted from a smaller number, the value that you get from that equation will be negative.

A number line looks something like this:

<__l___l___l___l___l___l___l___l___l___l___l___l___l__>
-3 -2 -1 0 1 2 3 4 5 6 7 8 9

When you subtract seven from five, you're subtracting seven "ones" from five, which will lead to negative two.

Hope this helped, and good luck on your math!
• The way i learned it you just add a small 1 above and slightly to the left of the digit,
but crosses out the number and rewrites it above with the borrowed digit. Is any one way right or better than the other?
• There is no better way, but one way might be easier or simpler too you. Use whichever one you like most.
• What do I do if the tens place, the bottom number is bigger?
• you borrow so if you have 40-12 you would do 40
-12
0-2 you cannot do so you take off 1 from the 4 so it is 3 and give it to the 0 so it is a 10 and 10-2 = 8
so you have 3 10
-1 2 then do 3-1=2
2 8
so you get 28 i hope this helps
• What is regrouping? I don't fully understand the concept in the video.
• Regrouping is when a number is bigger than the number you are subtracting by and you have to borrow. One example is 46-38. 6 is less than 8 but the whole number is bigger. Then because of this you will have to borrow one from 4 and make the 6 a 16. This means you are taking ten away from the 4. Now the number becomes 316. The `16 stands in the place where the 6 used to be. You then do 16-8 and 3-3. Your final answer will be 8
• Can you say, "thirteenth tens?"
• If you are referring to the problem in the video, the 13 is in the ones column, not the tens.
So, it is thirteen ones, not thirteen tens.