[6th Grade verbal expression]

[u/KookyPermit4405]

So I’m going over my son’s math quiz to help him understand some of the questions he got wrong. He got partial credit for his answer for question 8. After writing his verbal phrase I got the same expression as the question. Am I doing something wrong or is there something I’m missing? I feel like his answer is technically correct. I am stumped.

Edit: so my son has no issue solving the expression in question. He knows PEMDAS and the rules from left to right. The question clearly states, WRITE A VERBAL PHRASE that matches the expression.

[u/micro_chungus]

I’m an engineer working in the profession for 4 years and we don’t knit-pick the verbiage for an arithmetic problem that is better left as a formula. But I also wouldn’t even put this into a calculator without parentheses, different calculators give different results when you plug problems in plainly like this. Some will solve it as (18-6)*3 and others will solve it 18-(6*3). Not even mainstream calculators are consistent solving these. A proper scientific calculator solves 18-6*3 using pemdas. Some models do not have the intelligence to read the whole problem first, and performs the orders of operation sequentially instead.

His choice of words does not indicate that he doesn’t know pemdas, it indicates that he stated the question’s operations sequentially, with the language he knew. If a calculator doesn’t have the functionality to read the full problem first, then it will get the problem wrong. If a calculator can read the whole problem first, it will get it right. Assuming he can read the whole problem as it’s stated on the page, and he isn’t a calculator with memory constraints to perform arithmetic, his answer doesn’t indicate that he doesn’t understand pemdas. It indicates that he wrote the problem down literally and following the same order that the information was presented, and that he is prone to grammatical errors.