Alice Posted February 2, 2012 Share Posted February 2, 2012 I need to explain to my son why A -B + C = (A-B) + C but not A - (B + C) He is only 8 and only in Singapore 4A. So I need to explain it fairly simply. The reason it came up is that he did a problem wrong and I realized that the reason why is he did it the second way (added B and C together and then subtracted from A). I can just give him the rule that you have to do all subtraction and addition left to right. But I'm trying to understand better myself WHY so that I can explain it better to him. This is the kind of thing that was left out of my own math education. I figured I could also get a bunch of manipulatives out and we could play with them to show him visually. Still, I thought maybe there would be some math guru on here that could explain the why behind it to me. :) Quote Link to comment Share on other sites More sharing options...
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