Here you see seven tenths. If we divide each of those tenths into ten parts, we get seventy hundredths. Since all percents are out of 100, this is 70%
This one is super easy. All you really need to do is multiply the decimal by 100. Multiplying by 100 is the same as moving the decimal to the right two place values. So, all you really need to do is move the decimal two places to the right.