Question

What numbers can you make with 1, 2, 3, and 4? Using the operations of addition, subtraction, and multiplication, we can make many different numbers. You can use parentheses as many times as you like and each of the numbers 1, 2, 3, and 4 can be used at most once.

Answer 1

-23 to 28 and 30, 32, 36

Explanation:

These numbers can be made:

{-23, -22, -21, -20, -19, -18, -17, -16, -15, -14, -13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 32, 36}

For example,

• 36 = (1+2)(3)(4)
• -23 = 1 -(2)(3)(4)