Converting Between Decimal & Hexadecimal (AQA GCSE Computer Science)

To convert the decimal number 28 to hexadecimal, start by converting the decimal number to binary

Split the 8 bit binary number into two 4 bit numbers (nibbles) as shown below

Convert each nibble to its decimal value

0001 = 1 and 1100 = 12

Using the comparison table, the decimal value 1 is also 1 in hexadecimal whereas the decimal value 12 is represented in hexadecimal as C

decimal 28 is 1C in hexadecimal

To convert the decimal number 163 to hexadecimal, start by dividing the decimal value by 16 and recording the whole times the number goes in and the remainder

163 ➗16 = 10 remainder 3

In hexadecimal the whole number = digit 1 and the remainder = digit 2

Digit 1 = 10 (A)

Digit 2 = 3

Decimal 163 is A3 in hexadecimal

To convert the hexadecimal number B9 to decimal, take each hexadecimal value and convert it as decimal to 4 bit binary

Join the two nibbles to make an 8 bit number (byte)

Convert from binary to decimal

(1 x 128) + (1 x 32) + (1 x 16) + (1 x 8) + (1 x 1) = 185

Hexadecimal B9 is 185 in decimal

To convert the hexadecimal number 79 to decimal, start by multiplying the first hexadecimal digit by 16

7 ✖ 16 = 112

Add digit 2 to the result

112 + 9 = 121

Hexadecimal 79 is 121 in decimal