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 converts 101101 by grouping from the left and padding the wrong end. What slipped?
- He grouped from the left and padded the wrong end
- Each hex digit needs three bits
- His groups are already correct
Why do people bother with hex at all?
- Hex holds numbers binary cannot hold
- Hex removes the need for bits
- Two hex digits replace eight bits with nothing 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.
He grouped from the left and padded the wrong end · Grouping must start from the right with padding on the front, giving 2D.
Two hex digits replace eight bits with nothing lost · Hex is shorter to read and type, and converts back exactly.