103x2 =206
In normal counting (termed Arabic notation) each digit position is greated than the one to its right by a factor of ten. So 2045 is 1x5 + 10x4 +100x0 + 1000x 2 Another way to show the same sum would be: 100x5 + 101x4 + 102x0 + 103x2 In binary we use 2 instead of 10. We only need the digits 1 and 0, just as with normal numbers we don't need any digit higher than 9. So 1100100 would be: 20x0 + 21x0 + 22x1 + 23x0 + 24x0 + 25x1 + 26x1 We can work out all those powers and we get: 1x0 + 2x0 + 4x1 + 8x0 + 16x0 + 32x1 + 64x1 That simplifies to: 4 + 32 + 64 = 100