Practice Binary in CS Thinking

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Binary is a base-2 number system that uses only two digits, 0 and 1, to represent all values. Each digit position represents a power of 2, and computers use binary because electronic circuits have exactly two states: on and off.

Counting with only two states: on/off, yes/no, 0/1. Each extra digit doubles the count.

Showing a random 20 of 50 problems.

Example 1

medium
Convert 111121111_2 to decimal and explain why it equals 24โˆ’12^4 - 1.

Example 2

medium
Convert decimal 23 to binary.

Example 3

easy
In binary, what is 1+11 + 1?

Example 4

hard
Convert decimal 100 to binary by repeatedly dividing by 2 and recording remainders.

Example 5

easy
Convert the binary number 100121001_2 to decimal.

Example 6

medium
Halving a binary integer (discarding the remainder) corresponds to which simple bit operation?

Example 7

medium
Add the binary numbers 101121011_2 and 011020110_2.

Example 8

challenge
What decimal value is 11111111211111111_2 (eight 1s), and why is this number significant?

Example 9

medium
Doubling a binary number is done by what simple operation?

Example 10

easy
What is the decimal value of 1112111_2?

Example 11

medium
How many bits are needed to represent decimal 200?

Example 12

medium
Convert the decimal number 13 to binary using powers of 2.

Example 13

medium
Convert 110121101_2 to decimal.

Example 14

medium
Convert decimal 19 to binary.

Example 15

easy
Convert decimal 6 to binary.

Example 16

easy
How many digits does the binary number system use?

Example 17

medium
In binary, what is 1+1+11 + 1 + 1? Give the binary result.

Example 18

easy
Convert decimal 5 to binary.

Example 19

medium
How many bits are needed to represent decimal 64?

Example 20

easy
What is the rightmost (position 0) place value in binary?