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Class 7 Computer Science — Bigger binary numbers

Read and write binary numbers with several places, and work out how many different values a given number of bits can hold.

Name: ________________________

Before you start

Move along this line and think about which binary places you would need to reach each point.

048121620242832

The points that need only a single 1 — 1, 2, 4, 8, 16, 32 — are the place values themselves. Everything else is built by adding a few of them together.

  1. 1.Write the number 37 in binary.

  2. 2.In binary each place is worth twice the place to its right. The places so far are 1, 2, 4, 8, 16 and 32. What is the next place value after 32?

  3. 3.Match each binary number to its ordinary value.

    • 1000
    • 1111
    • 10010
    • 11000
    • 100000
    • 24
    • 15
    • 8
    • 32
    • 18

  4. 4.What is the largest number that fits in 4 bits?

    • a) 16
    • b) 14
    • c) 8
    • d) 15

  5. 5.With 3 bits you can write 000, 001, 010 and so on. How many different values is that altogether?

    • a) 3
    • b) 6
    • c) 9
    • d) 8

  6. 6.A byte is eight bits. How many different values can one byte hold?

    • a) 128
    • b) 64
    • c) 256
    • d) 512

  7. 7.How many different values can be written with 5 bits?

  8. 8.Write the number 20 in binary.

Answer key — Class 7 Computer Science — Bigger binary numbers

  1. 1. 100101
  2. 2. 64
  3. 3. 1000 → 8; 1111 → 15; 10010 → 18; 11000 → 24; 100000 → 32
  4. 4. d) 15
  5. 5. d) 8
  6. 6. c) 256
  7. 7. 32
  8. 8. 10100