Monday, October 15, 2012

Scary Subtraction

Subtraction is very scary for third graders and their teachers. It seems so simple but is so hard for little brains to grasp, especially when subtracting involves regrouping. There are so many steps and so many ways to make a mistake.

This is why we teach subtracting in such a different way now. We want kids to thoroughly understand what is happening in a sutraction problem. That does not mean there is validity in teaching kids how to "borrow" across numbers, but it is not valid to call it borrowing. In fact, you are not borrowing anything.

You are regrouping. You are literally taking a ten and regrouping it in to ten more ones in the ones place. Borrowing suggests that it stays a ten. But it doesn't.

I teach students how to subtract using these 5 methods:
Fair is Fair

Old School

Take a Penny

The most important thing for kids to remember and do is:
1. Always put the big # on top.
2. Before you start circle the largest digit in each place.
3. Think about the song.
Big on to?
No need to stop.
Big on the floor?
Go next door.
Take one ten,
That's ten ones more!

Here are the PowerPoint presentations that I use in class as my lessons. They will really help you understand how I teach and will provide a great review for your child.
There are some really great videos available to help understand subtraction.

Get Your Head in the Game! Check out this great online practice!
Subtraction Games
Subtraction Basketball

Subtraction Games
Match Up Subtraction
Subtraction Games
Subtraction with Regrouping Practice

Subtraction Games
Power Puff Girls Subtraction

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