yes, that's the simple solution. It reverses front to back. But I once enjoyed a much more complicated discussion of it by professional engineers and patent attorneys.

The math question was controversial because it was expressed in language rather than properly written. Divide 100 by 1/2 may mean by .5, in the customary sense of half of one, or it might be an adjective applying the fraction in to 100, and mean 50. I had my daughter write both answers, because I insisted the question wasn't clearly stated. It should be written as math, not mixed in with words, so you know what they want.

But my opinion was not much trusted, because I'm not widely regarded for my contributions to the field of math. Just as, when playing trivial pursuit, I told my team that Pb stands for lead, they all went on discussing it (potassium? or maybe it's that stuff, what's it called?) as if I had said nothing.

But Amos, the concept and symbol of zero were both invented, an Indian thinker, it's believed. The concept would surely re-emerge, but in a very different landscape of human endeavor than had been, because it's very handy. It's my hero, zero. What I'm saying is, the peculiar properties of symbols get mixed in, because true or real or not, we make them real eventually by interacting with them. Students whose language reflects our muddled expression of "eleven, twelve, thirteen" etc. trip up and slow down compared to those with a more sensible ten-one, ten-two, ten-three, etc. set of words. So when science looks at how we use words and symbols, and when we use them, things happen a little differently because of an interaction with them as tools. Song patterns of threes seem to have a special appeal, and that's also about how many times you have to take off a plane around a group of penguins for them to consider it normal, and stop leaning back until they fall over like a row of dominos.