4+2=6
6-3=3
3-1
2
3! = 6.
7 + 9 + 8*1
8 of them.
two that make 39 their difference is 11
(1+3)*2*4 = 32
Using only sums and differences, and not necessarily all four numbers, 1, 3, 9 and 27 will make all numbers from 0 to 40.
For example, by adding 1 + 1 + 1 ... (a total of 100 times).
8
Using 1, 2, and 3, you can make 27 whole numbers.
It can be: (5*6)-21 = 28
It can be: 2*3+4+1 = 11
11 x 2 x 2 - 2