This key facts covers Denary to Binary Conversion within Binary & Hex for GCSE Computer Science. Revise Binary & Hex in Memory & Storage for GCSE Computer Science with 15 exam-style questions and 22 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 6 of 14 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 6 of 14
Practice
15 questions
Recall
22 flashcards
Denary to Binary Conversion
Method 1: Place Value Method (Easiest for Exams)
Write out the place values, then work left to right deciding if each place value fits.
Example: Convert 156 to binary
Place values: 128 64 32 16 8 4 2 1
Number: 156
128 fits? YES → 1 (156 - 128 = 28 remaining)
64 fits in 28? NO → 0
32 fits in 28? NO → 0
16 fits in 28? YES → 1 (28 - 16 = 12 remaining)
8 fits in 12? YES → 1 (12 - 8 = 4 remaining)
4 fits in 4? YES → 1 (4 - 4 = 0 remaining)
2 fits in 0? NO → 0
1 fits in 0? NO → 0
Answer: 10011100
Method 2: Division Method
Repeatedly divide by 2, recording remainders from bottom to top.
Example: Convert 45 to binary
45 ÷ 2 = 22 remainder 1 ← LSB (rightmost) 22 ÷ 2 = 11 remainder 0 11 ÷ 2 = 5 remainder 1 5 ÷ 2 = 2 remainder 1 2 ÷ 2 = 1 remainder 0 1 ÷ 2 = 0 remainder 1 ← MSB (leftmost) Read remainders from bottom to top: 101101