In the decimal number system, 12.375 = 110^1 + 210^0 + 310^(-1) + 710^(-2) + 5*10^(-3). This is equal to 10 + 2 + 0.3 +0.07 + 0.005. The powers of 10 shift left in order to count in ones, tens, hundreds, and so on. The powers of 10 shift right to count in 1/10, 1/100, 1/1000, and so on.