I shall give it a go.
In each of these puzzles, you are given a number that you must construct out of several other numbers. You do this by taking the numbers and performing addition, subtraction, multiplication, and/or division operations on them. Each number must be used in the calculations exactly once, and only these four operations listed may be used. You may parenthesize your expression however you wish. For example, 10 may be obtained from 1, 1, 2, and 3, with the expression (3+2)×(1+1).