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  6. CH 4|Teacher Resource Sheets

Student Resource Book  |  
Year 4 (2B)

Number & Algebra

Chapter 4  |  Adding and subtracting by choosing a strategy

Teacher Resource Sheets

Getting Started

Eggs, eggs, eggs! (Getting started 4)

(You could use this sheet before starting the chapter so that students can share how they decide whether to add or subtract, and which strategy they should use.)

This displays the Getting started on page 85 of the Student Resource Book.

  • Teachers could use this to give students opportunity to create and share strategies to solve the addition and subtraction problems given.
  • It may be an idea to have the class work together on the first question, and then have students work in pairs to solve the others.
  • Remind students to check whether their answers make sense. They could share the strategies they used with other groups or as a class.

Adding and subtracting by choosing a strategy

Should I add or subtract? (Teacher Resource Sheet 13)

(You could use this activity for discussion prior to the mixed problems in Activity 3, page 93 of the Student Resource Book.)

The first of the two-page provides some prompts for approaching a problem, and the second provides problems teachers can use with the class to work through thus decision making process.

  • Encourage students to read the problem. At this stage the focus is on comprehension or understanding what is happening in the problem.
  • Once students have understood the problem, they can begin to think about and discuss the maths within it.
    • Does the problem involve combining, separating or comparing groups?
    • What words or numbers in the problem might be helpful?
    • It is helpful if students have a copy of the second page, so they can think about, underline or highlight these words or numbers independently prior to class discussion. You could ask students to suggest key words, for example, total, altogether, left, remain, more, less etc. Be aware though that while these words might help students decide whether to add or subtract, key words such as these, are often absent and sometimes misleading.
  • You could ask students to write down the equation for each problem and share which strategy they think will be most efficient for solving the problem.
  • The final step is important but often forgotten.  Discuss with students how they might decide that an answer makes sense.  Sometimes it is easier and more engaging to ask students to give examples that don’t make sense and then to explain why not.  For example, in question 1, a student may suggest an answer where the ladybird has less than 7 spots (this would not make sense but could be given as an answer if a student mistakenly subtracted).

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