Answer:
76 = 64 + 8 + 4 = 2⁶ + 2³ + 2², so bits 6, 3 and 2 have to be "1", ie., 01001100
20 = 16 + 4 = 2⁴ + 2², so bits 4 and 2 have to be "1", ie., 00010100
Explanation:
You have to decompose the number into a sum of powers of two (128, 64, 32,...).
Several ways to do this:
0) Trial and error. From left to right, try if you can fit the number in the sum, if it fits, use it (mark a "1"), if it doesn't, leave at "0".
1) Use the windows calculator in programmer mode. Enter the number and you'll immediately see the binary equivalent.
2) Repeatedly "integer divide" the number by 2, and note down a "1" if you have a remainder. If you note down from right to left, you have your binary representation.
