Question 1: Doubling a number means multiplying it by 2. The formula is: New amount = Original amount × 2. Correctly doubling 15 gives 30.

Answer: 30

Question 2: What is double 28?

Answer: 56

Question 3: If you double 0, what is the result?

Answer: 0

Question 1: Calculate the double of 37.

Answer: 74

Question 2: Double 125.

Answer: 250

Question 3: What is double 8?

Answer: 16

Question 4: Double 52.

Answer: 104

Question 1: A recipe calls for 200 grams of sugar. If you double the recipe, how much sugar is needed? Explain your reasoning.

Answer: 400 grams, because doubling 200 grams means 200 × 2 = 400.

Question 2: A garden is 15 meters long. If the length is doubled, what is the new length? Why?

Answer: 30 meters, because doubling 15 means multiplying by 2.

Question 3: A machine produces 50 units per hour. If production is doubled, how many units will it produce in one hour?

Answer: 100 units, because 50 × 2 = 100.

Question 4: A student scores 18 marks on a test. If they double their score, what is the new score? Is this a valid way to improve their score? Explain.

Answer: 36 marks; technically doubling the score increases it, but in real tests, scores are capped, so it may not be valid.

Question 1: A student says doubling 45 gives 90. They then mistakenly think doubling 0 gives 45. Identify and explain the mistake.

Answer: The mistake is in the second statement; doubling 0 results in 0, not 45, because doubling zero always gives zero.

Question 2: A pupil calculates double of 60 as 120 but then incorrectly writes the answer as 1200. Find and fix the error.

Answer: The error is adding an extra zero; the correct double is 120, not 1200.

Question 3: A student claims doubling 7 results in 77. What is the mistake, and what is the correct answer?

Answer: They mistakenly concatenated the digits; the correct double of 7 is 14.

Question 1: Construct a rectangle on the grid with length 4 units. Double both sides to form a larger rectangle. Label the new dimensions.

Answer: Dimensions 8 units by 4 units (or 4 by 8).

Question 2: Plot the graph of y = 2x for x from 0 to 5 on the grid. What does this graph represent in terms of doubling?

Answer: It shows that y is always double x; doubling x gives y.

Question 3: A bag contains 12 marbles. If the number of marbles is doubled, how many marbles are there now? Verify your answer.

Answer: 24 marbles; doubling 12 gives 12 × 2 = 24.

Question 1: A recipe for 4 servings requires 250 grams of flour. How much flour is needed if the recipe is doubled to serve 8? Explain your steps.

Answer: 500 grams, because doubling 250 grams gives 250 × 2 = 500.

Question 2: A car travels 60 miles in one hour. If the distance is doubled, how many miles are traveled? What assumption are you making?

Answer: 120 miles; assuming constant speed, doubling distance doubles the miles.