Do you remember factorials in maths? That’s where you have, say four numbers, and you want to find out how many four number combinations you can make with those four numbers. In Maths you write it as 4!. The answer is 4 x 3 x 2 x 1 = 24.

This type of calculation can be useful when you are working out probabilities and need to calculate how many possible combinations or permutations are possible.

Excel has a FACT function that simplifies the calculation. The above calculation is written as

=FACT(4)

You can use cell references

=FACT(A1)

You can’t use negative numbers and if you use zero, it will return 1.