When you divide a whole number by a decimal less than 1, the quotient is greater than the whole number. why?

One way to understand division is to look at it as repeated
subtraction.  When you "divide by" a divisor number, you're
asking "how many times can I subtract this divisor from the
dividend, before the dividend is all used up ?".

Well, if the divisor is ' 1 ', then you're taking ' 1 ' away from the
dividend each time, and the number of times will be exactly
the same as the dividend.

If the divisor is more than ' 1 ', then you subtract more than ' 1 '
from the dividend each time, and the number of times you can
do that is less than the dividend itself.

If the divisor is less than ' 1 ', then you only take away a piece of
' 1 ' each time.  You can do that more times than the number in
the dividend, because you only take away a piece each time.