We have been working on different addition strategies to help students add more easily and efficiently, and most importantly maintaining understanding of the place value of the numbers.
Today we worked on the "Opposite Change" strategy. Here's a brief overview of how it works.
Take the numbers 297 + 368.
Since 297 is very close to 300, we can change that number to a 300 from moving some amount from the other number - 368. 297 is only three away from 300, so we move three from the 368 to the 297, giving us:
300 + 365
Now the problem is MUCH easier to solve.
Suppose we had to add 748 + 155.
If we move two from the 155 to the 748, we now have:
750 + 153, which is again much easier to solve.
Another, more advanced way we could have done that would be to take 45 away from the 748 and move it to the 155, making:
200 + 703
We worked on several problems like these in class today, and the students took four problems like it home for homework. We will eventually work on the standard algorithm, but only AFTER the children have a firm understanding of how the numbers work. Please work on the Opposite Change strategy with your child and make sure they understand how to use it on their homework.
Tomorrow, we will work on another strategy called "Partial Sums".
1 comment:
That's a great method, and it's a lot easier than the "borrowing" brain-numbing stuff.
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