It means that you have to put the decimal point in the quotient exactly above the decimal point in the dividend.
Step-by-step explanation:
In the picture attached, the decimals chart is shown. There you can see where you have to put the decimal point in the quotient when you are dividing a decimal number by a whole number.
Rounding up is a rule that is used, no matter what the value is. We round numbers up to get a better estimate for our answers. The memory cue for dividing by a whole number "up" just means that you will be bringing the decimal up.
