En anglais

Four bits in one digit

Computing · Computer Systems · ages 14-15

Name ______________________ Date ____________

How many bits does one hex digit stand for?
- 4
- 8
- 2
What value does the hex digit A stand for?
- 11
- 10
- 16
The hex digit F stands for the bits 1111.
Circle one: True False
What is the hex number 2F in decimal?
Answer: ______________
What is 10100110 in hex?
- 6A
- A6
- B6
What is 11011110 in hex?
- DE
- ED
- CE
Tom groups 101101 incorrectly. Which rule gives the correct hex value?
- Group right, pad left: 0010 1101 gives 2D.
- Group left, pad right: 1011 0100 gives B4.
- Use three bits per digit: 101 101 gives 55.
Why do people use hex for binary values?
- Hex can represent values that binary cannot represent.
- Hex removes the need to store any bits in memory.
- Two hex digits show eight bits with no value lost.

Answer key

For grown-ups. Fold this page away before handing over the rest.

4 · Four bits make sixteen patterns, exactly matching the sixteen digits.
10 · Digits run 0 to 9, then A continues the count at 10.
True · F is 15, and 15 in four bits is 1111.
47 · The 2 sits in the sixteens place: 2 times 16 plus 15 is 47.
A6 · Split into 1010 and 0110, which are A and 6.
DE · Split into 1101 and 1110, which are D and E.
Group right, pad left: 0010 1101 gives 2D. · Groups begin at the right. The short group is on the left, so add two zeros before it: 0010 1101, or 2D.
Two hex digits show eight bits with no value lost. · Each hex digit maps to four binary bits, so two hex digits replace eight bits while keeping the same value.