The Magic of Remainders
Hook about how remainders build the new number.
Master the 'Repeated Division' method for converting integer decimal numbers into binary, octal, or hexadecimal.
Hook about how remainders build the new number.
Explain the 4 steps to convert decimal to any base.
Converting a decimal (base-10) number to binary, octal, or hexadecimal might seem complex, but it relies on one universal algorithm: repeated division.
Step 1: Divide your given decimal number by the base value () of the target number system (e.g., 2 for binary, 8 for octal, 16 for hex).
Step 2: Note the remainder of this division. This remainder becomes part of your newly converted number.
Visual of 65 divided by 2.

Repeatedly divide by 2, collect remainders bottom-up.
Explain how to handle remainders greater than 9 in Hex.
The exact same method works for base 8 and base 16. You just swap out the divisor. However, hexadecimal introduces a unique challenge you must watch out for.
If your division yields a remainder of 10, 11, 12, 13, 14, or 15, you MUST convert it to its Hexadecimal symbol (A, B, C, D, E, F) before writing your final answer. Leaving it as a two-digit decimal will ruin your conversion.
Fill blanks for converting 65 to Octal.
Convert 122 to binary.
Based on the repeated division process, what is the binary equivalent of the decimal number 122?