How many consecutive zeros are there at the end of 100! (100 factorial) ?
There are 24 zeros on the end of 100!
The clever bit here is thinking what numbers when multiplied together will end in a zero.
So the product of what numbers when multiplied ends in a zero:
1. When one of the things being multiplied ends in zero itself
2. A number ending in 5 multiplied by an even number
Below is tabulated the origin of all the zeros:
So that's it then there are 24 zeros at the end of 100!