What is 40 percent of 52 dollars?

Answer 1

This is pretty easy to figure out in your head, actually. First, remember that 40% means 40 out of 100, or 40/100. We can simplify this to 4/10 for our purposes. (Yes, I know it can further simplify to 2/5, but that's not going to work as nice for what I plan to do here.) 4/10 means to multiply by 4 and then divide by 10 -- but we don't have to do it in that order! Let's divide by 10 first, which is easy, since all we have to do is slide the decimal point over one place to the right. Yes, it may not look like it, but there is an implied decimal point in 52, just to the right. Since it's not actually needed in whole numbers, however, it's never drawn in, which is why it's implied. But let's make it visible and move it over. 52/10 is 5.2. Now we need to multiply by 4. You could break out a pencil and paper, or a calculator, to figure it out, but 4 is an easy number to multiply in your head, because you just have to double the other number twice. (That's the same as multiplying by 2 twice, and 2x2=4, which is why that works.) So, 5.2 doubled is 10.4, and 10.4 doubled is 20.8. In monetary terms, that's $20.80.

If you wanted to further convince yourself that this is at least a reasonable answer, remember that 40% is a little less than 50%, or half. So if your answer is a little less than half of what you started with, you're probably good. And since half of $52 is $26, and $20.80 is a little less than $26, I think you're in good shape!