Binary, bits and bytes
Answers are for parents and teachers.
1
Five lamps in a row are on, on, off, on, off. Write the pattern if on = 1 and off = 0.
11010.
2
A file is 6 KB, with 1 KB = 1024 bytes. How many bytes and how many bits is it?
6 × 1024 = 6144 bytes; 6144 × 8 = 49152 bits.
3
How many patterns can 12 bits make?
2¹² = 4096.
4
A lock has 9 different codes. How many bits are needed at least to write them as different patterns?
4 bits: 2³ = 8 is too few and 2⁴ = 16 is enough.
5
Explain in two sentences why a byte can show 256 different patterns.
A byte has 8 bits and each bit has 2 possible values. The choices multiply: 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 2⁸ = 256.