Multiplying and dividing 0 Overview Using this Resource Connecting to the Curriculum Marking Student Responses Working with Students Further Resources This task is about finding correct answers to maths problems with mistakes. Some children made small mistakes in their calculations. In the following questions work out what the correct answer should have been. Question 1Change answer a) Sanaj multiplied a number by 2 instead of dividing it by 2. The answer he got was 32. a) Sanaj multiplied a number by 2 instead of dividing it by 2. The answer he got was 32. What should his answer have been? Question 1Change answer b) When Sara multiplied a number by 3 instead of dividing it by 3, the answer she got was 36. b) When Sara multiplied a number by 3 instead of dividing it by 3, the answer she got was 36. What should her answer have been? Question 1Change answer c) When Min multiplied a number by 5 instead of dividing it by 5, the answer she got was 100. c) When Min multiplied a number by 5 instead of dividing it by 5, the answer she got was 100. What should her answer have been? Task administration: This task is completed with pencil and paper or online with auto-marking. Levels: 3, 4 Curriculum info: Maths, Number and Algebra, Equations and expressions Keywords: multiplication, division, equations Description of task: Students work out the correct answers to arithmetic problems given an incorrect solution. Learning Progression FrameworksThis resource can provide evidence of learning associated with Using symbols and expressions to think mathematically, set 4Using symbols and expressions to think mathematically, sets 4-5 within the Mathematics Learning Progressions Frameworks.Read more about the Learning Progressions Frameworks. Answers/responses: Y6 (06/1997) Y7 (06/1997) a) 8 easy easy b) 4 moderate easy c) 4 easy easy Diagnostic and formative information: Common error Likely reason a) b) c) 16 12 20 Solved by dividing 'answer' by the divisor, i.e., 16 = 32 ÷ 2, 12 = 36 ÷ 3, 20 = 100 ÷ 5. This gives the original number, not the answer. c) 25 Multiplies 5 × 5. 1 or 2 out of 3 correct. Does most calculation correctly but fails to exploit the close similarity of the questions. Addition and Multiplication boxes