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Class 9 The World of Algorithms worksheet
CBSE Mathematics. Step-by-step procedures, column addition, Euclid's algorithm for the HCF. Every sheet has 20 questions in three sections and an answer key, and the numbers 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.
An algorithm is:
- a type of number
- a formula for area
- a guess that usually works
- a finite list of clear steps that solves a problem
Answer
(d) a finite list of clear steps that solves a problem
- 2.
Using Euclid's algorithm, HCF(126, 99) is:
- 9
- 27
- 18
- 11
Answer
(a) 9
126 = 99 × 1 + 27; 99 = 27 × 3 + 18; 27 = 18 × 1 + 9; 18 = 9 × 2 + 0
- 3.
How many divisions does Euclid's algorithm make to find HCF(88, 12)?
- 4
- 3
- 1
- 2
Answer
(d) 2
88 = 12 × 7 + 4; 12 = 4 × 3 + 0
Section B · short answer
- 4.
Use Euclid's algorithm to find the HCF of 442 and 416.
Answer
26
442 = 416 × 1 + 26; 416 = 26 × 16 + 0
- 5.
Find HCF(18, 15) by repeated subtraction (keep replacing the larger number by the difference).
Answer
3
(18, 15) → (3, 15) → (3, 12) → (3, 9) → (3, 6) → (3, 3)
Section C · long answer
- 6.
A floor is 1100 cm by 1000 cm. Find the side of the largest square tile that fits exactly, and the number of tiles needed.
Answer
100 cm; 110 tiles
1100 = 1000 × 1 + 100; 1000 = 100 × 10 + 0; (1100 ÷ 100) × (1000 ÷ 100)
Fresh sheets for your child
In the app, every The World of Algorithms 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.