Math CentralQuandaries & Queries


Question from Jeannine, a teacher:

What is 20 and 3/5 of 10? Question is written exactly this way.
Is this 20 3/5 times 10 (103/5 times 10), or is it 20 and (3/5 times 10)?

Hi Jeannine,

I find this question very disturbing. Mathematical language and notation should be used to make a statement clear and unambiguous but this looks to me to be an attempt to be confusing. I expect that you are to read and as plus and of as multiplication so the question becomes

What is $20 + \frac35 \times 10?$

An then, since multiplication takes precedence over addition this becomes

What is $20 + \left( \frac35 \times 10 \right)?$


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