150-143=
If you were me you would re-write it with the 150 on top of the 143 and then borrow.
But if you were W or J and using Singapore math you might do it like this.
150-143=
150-140=10
10-3=7
150-143=7
Does that make sense? It took me a minute to get whythey were doing it that way. It looks like it would take longer but it doesn't. You can actually do this in your head faster than I can do it on paper using the old borrowing method.
So what do you think?? Which method do you prefer? And if you're a homeschooler, how do you teach math?
Wow, that is almost exactly the formula my oldest figured out on her own. She taught herself how to do the problems because carrying confused her--the only difference is that she combines one of the steps in her head.
ReplyDeleteI am a 10-7 kind of gal. I do a lot of mental math and that helps make it quicker. You'll probably notice they come up with all kinds of little tricks to help them do things quicker in their heads if they are already doing that one :)
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