Two Digit Subtraction for First Grade Math

Video Transcript

"I would teach them about two or more digits with addition for many days, maybe weeks before introducing many digits subtraction. But when you feel that they're ready you can go to your subtraction. And again, start out simple. Start out with problems that don't involve borrowing and teach them about the minus sign here. Teach them about how the minus sign and the plus sign can change an entire problem. So, to look carefully because down the road you're going to switch it up and give them addition and subtraction problems on the same work sheet. And you can be firing off a lot of work sheets at this point and we'll do 6A5 is 1. 5A2 is 3. 35. And then you can start to teach them about borrowing. 2 minus 8, 2 is too small to take 8 from so it has to borrow from Mr. 3; borrows 1. Mr. 3 turns into a 2 and Mr. 2 get's that 1 as a 10, turns in to a 12. 12A8 is 4. 2A1 is 1. And once they've mastered that, again we're talking about several days before we move on to the next higher level of problem. And then we can talk about 3 or more digits. Again, with borrowing. And in this case there's double borrowing when you have a zero. Don't forget to put problems with zeros. That 0 has to borrow from the 3 before he can even give anything to the 2. And the 2 becomes a 12. 12A6 is 6. And the 10 becomes a 9. 9A4 is 5 and just drop down the 2. Teach them about just dropping down when there's an extra number. 2 on the end. And then you can move on to higher level problems from there."