4.2.5 PEMDAS Brainstretcher

Calculator symbolThe calculator can be accessed in the left-hand side bar under Toolkit.

Activity symbol Activity: Brainstretcher

Can you add parentheses to these calculations to make them correct?

(a) one plus three multiplication four equals 16

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Comment

None of the calculations are correct as they stand. Try adding parentheses so that the order of operations changes. Trial and error will get you there.

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Answer

(a) equation sequence open one plus three close multiplication four equals four multiplication four equals 16

(b) three plus seven minus two squared equals 28

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Answer

(b)equation sequence three plus open seven minus two close squared equals three plus five squared equals three plus 25 equals 28—not an easy one to spot! So well done if you did.

(c) two plus three multiplication four minus one equals 15

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Answer

(c) equation sequence open two plus three close multiplication open four minus one close equals five multiplication three equals 15

Here’s what you have already learnt in this section:

  • When you carry out a complicated calculation with more than one operator, follow the PEMDAS code:
  • Addition and subtraction are on the same level as each other as are multiplication and division.
  • Remember the addendum:
  • The calculator is programmed to follow this rule!

4.2.4 Moving Left to Right

4.2.6 PEMDAS Performed By Hand