Sunday, February 20, 2011

Math: Subtraction

We are currently on the subtraction unit in our Singapore 1A books. To go along with our unit we have been adding in a few extras.

I had picked up some 10 sided dice at the homeschool convention last year (a great tool that we’ve used LOTS) I am using them for lots of games, but you could use other dice for the following games, as well as drawing numbers randomly some way.

Three Strikes Game

The first game I found and printed from Mathwire (a new favorite site). I had seen it at CHEA this last year in a math workshop I attended so instead of making my own board I went ahead and printed it off. This particular board is actually for addition but we have modified it for subtraction (eliminating the 10 and 11 spots as options).   IMG_0014

You start the game by picking two numbers on your board (we used the pink and orange sticky notes to identify them) as “strike zones” if you get those numbers it qualifies as a strike – if you get three you lose.

We place markers on all of the remaining numbers and roll 2 of our 10 sided dice and subtract them (the lower number from the higher/total number). We take the answer and remove the marker from our game board. The first one to remove all his markers without striking out wins!!

Subtraction Board

Singapore had a really great approach for how I could group the subtraction facts together to introduce them. I made a set of subtraction fact flashcards and pulled out one of our colorful tri-fold boards and started building a subtraction fact chart.

imageAs we introduce new facts to memorize and master we add them to our board.

IMG_0016

Since this picture we have also attached our games to the board for easy access.

This was a great idea, Treyton has loved using this board, and uses it as his “shop” (like daddy) – he says it’s his work and he will sit and do some of his school behind it during school or play behind it when we’re not doing school.

Number Sentence Creator

I saw on another blog (somewhere) this idea of making a number sentence creator worksheet. This is one area that Treyton has struggled with the most. He does well with solving word problems, hands on problems, addition and subtraction games and even solving number sentences when they are given to him. He struggles however to turn a word problem into a number sentence or to create number sentences himself.

I will have Treyton roll a ten sided die (or our number education cubes) and record five numbers across the top, we will then work through creating different number sentences from these numbers and then solving them.

imageWe’ve been using these tools quite a bit in the last week and have really enjoyed them. Treyton seems to be learning a lot, and having fun in the process. Is there anything better?

1 comment:

cahanbury said...

What great ideas! We're doing some subtraction here as well and I can't wait to try these!