Nearest 10

12-14-2010, 04:26 PM
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I agree that visual are very helpful for many second graders. I have better luck with number lines, though. I've noticed a lot of kids have trouble understanding why 12 is closer to 10 when you have to go up a line... When I use a 100 chart, we move spaces like we're playing a board game and count how many we have to move back and how many we have to move forward to decide which is closest.
I've also had many kids who seem to just pick a random multiple of 10 to round off. We've been talking a lot about how the lowest possible 10 is part of the name of the number, and the other choice is the next 10 up. For example, if we're looking at the number 36, we can hear that 30 is part of the name of the number so that count by 10 is one of the choices. The next 10 -- 40 -- would also be a choice. Then we look, count, or try to apply the "5" rule to decide which one to use. Hopefully that makes sense.
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