IGCSE Computer Science Paper 1 Crossword: 1.1 Number Systems (Modules 3–17)
Name:
Date:
Class:
✎
Crossword
Read each clue and write the matching term in the grid. Numbers in brackets show the letters in each word.
1
2
3
4
5
6
7
8
Across
- 2. Word 3 of the term in 1 Down: ______ place _____ (5)
- 3. Word 1 of the term in 2 Down: ___ the place ______ ____ a 1 (3)
- 5. How many different digits a ______ system uses: denary is ______ 10 (digits 0-9), binary is ______ 2 (digits 0-1) and hexadecimal is ______ 16 (digits 0-9 and A-F). Word 1 of: ______ ____ (6)
- 6. Word 2 of the term in 5 Across: ______ ____ (4)
- 7. Word 5 of the term in 2 Down: ___ the place ______ ____ a 1 (4)
Down
- 1. Each ______ column is worth 10 times the column to its right (1, 10, 100, 1000). A number is the sum of each digit times its column ______, e.g. 345 = 300 + 40 + 5. Word 1 of: ______ place _____ (6)
- 2. To convert 16-bit binary to denary, write the place ______ (32768 down to 1) over the bits, skip the 0 columns, then ______ the ______ that have a 1 under them. Leading zeros ______ nothing. Word 4 of: ___ the place ______ ____ a 1 (6)
- 4. ______ the denary number by 16 again and again. Read the remainders from last to first, writing 10 to 15 as A to F. Check by converting the hex back to denary. Word 1 of: ______ by 16 (6)
- 6. Work from 32768 down to 1. Write 1 and subtract if the place value fits in the remainder, otherwise write 0. Keep leading zeros so the answer has 16 digits. Word 4 of: ______ to 16-___ binary (3)
- 8. Multiply each ______ digit's value (A-F = 10-15) by its column value (1, 16, 256, 4096), then add the results. Example: 2F = 2 x 16 + 15 = 47. Word 1 of: ___ to ______ (3)
Answer Key
IGCSE Computer Science Paper 1 · Modules 3–17
1D
2V
A
L
U
E
A
N
L
3A
D
4D
5N
U
M
B
E
R
I
E
Y
V
6B
A
S
E
I
I
D
7W
I
T
8H
E
E
X
Across
2VALUE — Word 3 of the term in 1 Down: ______ place _____
3ADD — Word 1 of the term in 2 Down: ___ the place ______ ____ a 1
5NUMBER — How many different digits a ______ system uses: denary is ______ 10 (digits 0-9), binary is ______ 2 (digits 0-1) and hexadecimal is ______ 16 (digits 0-9 and A-F). Word 1 of: ______ ____
6BASE — Word 2 of the term in 5 Across: ______ ____
7WITH — Word 5 of the term in 2 Down: ___ the place ______ ____ a 1
Down
1DENARY — Each ______ column is worth 10 times the column to its right (1, 10, 100, 1000). A number is the sum of each digit times its column ______, e.g. 345 = 300 + 40 + 5. Word 1 of: ______ place _____
2VALUES — To convert 16-bit binary to denary, write the place ______ (32768 down to 1) over the bits, skip the 0 columns, then ______ the ______ that have a 1 under them. Leading zeros ______ nothing. Word 4 of: ___ the place ______ ____ a 1
4DIVIDE — ______ the denary number by 16 again and again. Read the remainders from last to first, writing 10 to 15 as A to F. Check by converting the hex back to denary. Word 1 of: ______ by 16
6BIT — Work from 32768 down to 1. Write 1 and subtract if the place value fits in the remainder, otherwise write 0. Keep leading zeros so the answer has 16 digits. Word 4 of: ______ to 16-___ binary
8HEX — Multiply each ______ digit's value (A-F = 10-15) by its column value (1, 16, 256, 4096), then add the results. Example: 2F = 2 x 16 + 15 = 47. Word 1 of: ___ to ______