For 7 × 5 using a calculator should not even be a thing for most people. Sure, some people just can't do the basic tables, but most people should be able to tell how much seven €5 items cost in a supermarket. If you could do this as a teenager, but lost that skill afterwards, you are just sacrificing your brain.
Yes I thought about that after writing it and should've used an example with bigger numbers. But I didn't want to ninja edit too much. I think the point came across.
