Hmm…
As if math wasn’t hard enough, now we’re learning that elementary school children have to learn how to figure out math problems that are delivered in word format? And it only gets harder from there, young one—sooner or later, you’ll discover that actual letters will replace numbers.

For the time being, we can appreciate the innocent mind of the OP’s child. After correctly answering who had more money (Bobby and his four dimes or Amy and her 30 pennies), they were asked to “show their thinking.” Of course, the kid drew a picture of themselves literally thinking about who had more money.