100 = 64 + 32 + 4 = 2 ^ 6 + 2 ^ 5 + 2 ^ 2 = 1100100 #### 10 ^ -1 = 0.1 10 ^ -2 = 0.01 10 ^ -3 = 0.001 #### 2 ^ -1 = 1/2 2 ^ -2 = 1/4 2 ^ -3 = 1/8 binary 1010.1010 = 2 ^ 3 + 2 ^ 1 + 2 ^ -1 + 2 ^ -3 = decimal 10.625