To solve this, look for some factors which could go into the number. Since it ends in a 0, the number 10 is a factor. Since 990 is the product of these factors (meaning they are multiplied together) you can divide out the 10, since division is the opposite of multiplication. This leaves you with the number 99. You can repeat this same process again, realizing that 9 must be a factor of 99 because both digits are 9. If you divide out the 9, this leaves you with 11.
Thus, we know 9*10*11 equals 990. Also, these numbers are consecutive because they increase by 1 each time.
The sum of the numbers is 9+10+11, whicj Iis 30.
ANSWER: 30
