31A (base sixteen)   = 

   3 × sixteen2 + 1 × sixteen1 + A × sixteen0

Converting a Repⁿ to Decimal Repⁿ

As usual, to represent the number using base ten, write the base and "digits" in base ten, and then do the arithmetic:

31A (base sixteen) = 3 × sixteen2 + 1 × sixteen1 + A × sixteen0

                   = 3 × 162 + 1 × 161 +  10 × 160

                   = 3 × 256 + 1 × 16 +  10 × 1  =  79410

You don't have to remember powers of 16 to do this conversion. All you need is powers of 2. For example, 16²   =   2⁴ ×2⁴   =   2⁸   =   256.

As another example:   16³   =   2⁴ ×2⁴ ×2⁴   =   2¹²   =   2² ×2¹⁰   =   4K

1B2 = ____  × sixteen2 + ____ × sixteen1 +  ____ × sixteen0

1B2 = ____10 × 162 + ____10 × 161 +  ____10 × 160

1B2 = ____10 × ____10 + ____10 × ____10 +  ____10 × ____10

1B2 = ____10