He offered the “four fours” problem as an example: Students have four number fours, and can use whatever operations necessary to get to another number, such as 10.

The problem with PEMDAS is that it excludes the “from left to right” requirement for multiplication and division (#3 below) and addition and subtraction (#4 below).

If you want to know for sure, try your hand at this basic math problem. It's harder than it looks — even if you think you have a solid grasp of good old PEMDAS. The problem originally went… ...

Sometimes BODMAS is just PEMDAS by another name. And no, the answer is not 100. By Steven Strogatz Mathematical Twitter is normally a quiet, well-ordered place, a refuge from the aggravations of ...