Question 1: Calculate the HCF of 12 and 18.

Answer: 6

Question 2: Find the HCF of 8, 12, and 20.

Answer: 4

Question 3: What is the highest common factor of 15 and 25?

Answer: 5

Question 4: Construct a triangle with sides that have an HCF of 3. Use the grid to draw the sides.

Answer: Students will draw sides with lengths, e.g., 6, 9, 12, all divisible by 3

Question 5: Calculate the HCF of 21 and 28.

Answer: 7

Question 6: A box contains small cubes with side lengths of 2 cm, 4 cm, and 6 cm. Find the largest size of cube that can evenly fit into all dimensions.

Answer: 2 cm

Question 7: Identify the common mistake made when finding the HCF of 16 and 24 if a student incorrectly states it is 8. Explain and correct the mistake.

Answer: Common mistake: Only considering common multiples or incorrect factors. Correct: Find the factors of both (16:1,2,4,8,16; 24:1,2,3,4,6,8,12,24). The HCF is 8.

Question 8: Find the HCF of 9, 15, and 27.

Answer: 3

Question 9: A factory produces batches of small parts in quantities of 18, 24, and 30. What is the maximum number of complete sets that can be made from each batch?

Answer: 6

Question 10: Find the HCF of 14 and 35. Then, check if the HCF divides both numbers evenly.

Answer: HCF is 7; yes, 7 divides both 14 and 35 evenly

Question 11: Identify and explain a common mistake when students forget to consider only the common factors when finding HCF.

Answer: Mistake: Considering only multiples or larger factors, leading to incorrect HCF. Correct approach: Find all factors of each number and select the largest common one.