[Elsie]

If you increase the size of an electron to the size of the earth, it’ll weigh less than a feather.

I found why I am confused.

You speak of SIZE in this statement but your answer deals with MASS.

This would be fine if the DENSITY of the two items being compared were the same.

I am now trying to search for the density of an electron but am coming up short.

[Kevmo]

You asked for ‘handy’ math. Increase the size of the thing, increase the weight of it by the same number of orders of magnitude.

You had a lot of trouble with orders of magnitude before, as I recall. You were off by more than 100 orders of magnitude. I can see why you’re confused. Maybe this exercise will get you over that threshold of understanding.