3 is smaller than 20, so it doesn’t look like you can divide 20 into 3, because 3/20 is a fraction. But fractions can be turned into decimal fractions and a decimal point is used to separate the whole number part of a mixed number from the fractional part. After the decimal point we have tenths, then hundredths, thousandths and so on. To divide by 20 we divide first by 10, so 3 divided by 10 is 3 tenths written as .3. The period (decimal point) is so tiny that we protect it by putting a zero in front to get 0.3, that’s 3 tenths. If we add another zero we have 30 hundredths. Since 20 is twice ten and we are dividing 3 by 20, we now need to divide 0.30 by 2. Well, 30 divided by 2 is 15, so 3 divided by 20 is 0.30 divided by 2, which is 0.15. (So 3/20 is one tenth plus 5 hundredths.)