Take the number 9999.
Divide it by 37: = 270.2 (approximately)
Take the greatest integer which is less than 270.2. It is 270.
The number 270*37 = 9990 is your answer.
Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website! A shortcut that can be used to get to the answer quickly is to know that 37*3 = 111.
Therefore, any 3-digit number of the form AAA is a multiple of 37.
In particular, 999 is a multiple of 37; so 9990 is also a multiple of 37.
And clearly adding another 37 would make a number that is no longer 4 digits.