Find the missing numbers in a grid which has some numbers and some missing. This is based on a sheet another teacher gave to me and I have made it electronic (spreadsheet) so that you make as many games as you want as well as extended it to include:Addition using numbers: 0 to 20, 0 to 50, 0 to 100, -20 to 20, -50 to 50 and -100 to 100.Multiplication using numbers: 0 to 5, 0 to 10, 0 to 12, 0 to 20, -5 to 5, -10 to 10, -12 to 12, -20 to 20.The only 'spreadsheet' skill required is to press F9 to