M3.2.6 For the adult

Order of operations

What is 3 + 4 × 2?

What this chapter teaches

Calculations with several operations are worked in an agreed order: brackets, then multiplying and dividing, then adding and taking away, left to right inside a step. Brackets change the order, so they can change the answer.

Three questions to ask

There is no one right wording. Listen for the idea.

  1. Why is 3 + 4 × 2 equal to 11 and not 14?
  2. What do the brackets do in (3 + 4) × 2?
  3. Where would you put brackets to make 2 + 3 × 4 equal 20?

After the chapter, the learner can

  • Work out 3 + 4 × 2 in the right order
  • Use brackets to change the order of working
  • Put in brackets to make 2 + 3 × 4 equal 20

What they copy into their notebook

Order: brackets first. Then × and ÷. Then + and −. Inside a step, work left to right. 3 + 4 × 2 = 11, but (3 + 4) × 2 = 14.

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