Forget-Me-Not Posted November 19, 2013 Share Posted November 19, 2013 Okay, from MM 5A 3 - 0.9 ÷ (1 - 0.7) = We solved it as 3 - 0.9 ÷ (0.3), therefore 3 - 3 = 0. The answer key says the answer is 7, which necessitates doing the subtraction before the division. Am I missing something? I thought order of operations went Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. Quote Link to comment Share on other sites More sharing options...
Leav97 Posted November 19, 2013 Share Posted November 19, 2013 Sounds like an error in the answer key. Quote Link to comment Share on other sites More sharing options...
Forget-Me-Not Posted November 19, 2013 Author Share Posted November 19, 2013 I think that's what I've decided too. I just wanted to make sure I wasn't overlooking something big :) Thanks! Quote Link to comment Share on other sites More sharing options...
Dana Posted November 19, 2013 Share Posted November 19, 2013 Do be careful though that you note that division and multiplication are equal....so if you see division before multiplication, you'd do division first. Quote Link to comment Share on other sites More sharing options...
Forget-Me-Not Posted November 19, 2013 Author Share Posted November 19, 2013 Do be careful though that you note that division and multiplication are equal....so if you see division before multiplication, you'd do division first. Right, same with addition/subtraction correct? I did know that, I just use the old mnemonic Please Excuse My Dear Aunt Sally to keep it stuck in my head ;) Quote Link to comment Share on other sites More sharing options...
Dana Posted November 19, 2013 Share Posted November 19, 2013 Right, same with addition/subtraction correct? I did know that, I just use the old mnemonic Please Excuse My Dear Aunt Sally to keep it stuck in my head ;) Correct. I hate PEMDAS though because I have students regularly do multiplication first because of that mnemonic. As long as you don't propagate the error that multiplication is before division, you're fine with me :) Quote Link to comment Share on other sites More sharing options...
kiana Posted November 20, 2013 Share Posted November 20, 2013 You might toss her an email about the error in the key (but it is an error). Quote Link to comment Share on other sites More sharing options...
alef Posted November 20, 2013 Share Posted November 20, 2013 I agree it looks like an error. Quote Link to comment Share on other sites More sharing options...
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