Worksheets › Class 8 › A Story of Numbers: Thinking Puzzles
Class 8 · Computational Thinking and AI worksheetA Story of Numbers: Thinking Puzzles
CBSE Computational Thinking and AI. Binary, ternary and base-5 numbers, binary pipes, Roman numerals and patterns, fewest swaps to sort. Every sheet has 20 questions in three sections and an answer key, and the questions change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
In base 2, the only digits used are:
- 0, 1 and 2
- 0 to 9
- 1 and 2
- 0 and 1
Answer
(d) 0 and 1
- 2.
What is 235 in binary?
- 11101011
- 11101010
- 111010110
- 11010111
Answer
(a) 11101011
235 = 128 + 64 + 32 + 8 + 2 + 1
- 3.
What is the binary number 1000110 in decimal?
- 71
- 49
- 69
- 70
Answer
(d) 70
64 + 4 + 2
Section B · short answer
- 4.
Why can the digit 2 not appear in a binary number?
Answer
In base 2 two of a place make one of the next place, so the digits are only 0 and 1.
- 5.
Binary pipes come in lengths 1, 2, 4, 8, 16, 32, 64 and 128 inches, one of each. Which pipes together measure exactly 113 inches? Write them from longest to shortest.
Answer
64, 32, 16, 1
113 in binary is 1110001
Section C · long answer
- 6.
Write 173 (a) in binary (b) in base 3 (c) in Roman numerals.
Answer
(a) 10101101; (b) 20102; (c) CLXXIII
powers of 2 and of 3; 173 = CLXXIII
Fresh sheets for your child
In the app, every A Story of Numbers: Thinking Puzzles sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
Coming soon for Android and iPhone.