Rich tasks
- This is an open-ended activity that requires students to investigate making food choices at a beach food truck and involves addition, subtraction, multiplication and division. The task can be given at the start of a topic and done as the students gain enough understanding to complete it or given as a homework task.
- The food truck
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1. The food truck
- Encourage students to work in an organised way to record all the suitable choices and their costs.
- Students could work in groups to create their own food truck menu.
Adding and subtracting page 150
- Understand whether addition or subtraction should be used to solve a problem.
- Use addition or subtraction to solve a problem.
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Teacher notes
- Students need practice at reading problems and being able to explain what is happening in their own words, before deciding which operation is needed and before writing an equation or beginning to solve the problem.
- Deciding whether to add or subtract can be a difficult choice for some students. You could model ways to ask questions that will help their understanding of the problem, for example:
- Are groups being joined to find a whole? (addition)
- Is a group being separated into parts? (subtraction)
- Are groups being compared? (subtraction or addition with part unknown)
- Once the equation is written down students can then decide which strategy they might use to find the answer and do the calculation.
- Some students may choose to do reversibility and use addition to solve a subtraction problem. However, they still need to understand that they are finding the difference between two numbers.
- Encourage students to check their answer.
- Does it answer the question? For example, if the question asks “How many minutes altogether?”, does the answer to the addition equation include the word ‘minutes’?
- Does it make sense? For example, the answer to an addition problem is either the same or bigger, and the answer to a subtraction problem is either the same or smaller.
Checking answers like this is a very important concept that helps students with estimation.
- Go to Activity 1 page 150 in the Student Resource Book to show the process, which you could use to support students’ problem solving in this chapter.
Multiplying and dividing page 151
- Know whether multiplication or division should be used to solve a problem.
- Use multiplication or division to solve a problem.
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Teacher notes
- Students need practice at reading problems and being able to explain what is happening in their own words, before deciding which operation is needed, writing an equation, or beginning to solve the problem.
- Key to deciding whether multiplication or division rather than addition or subtraction should be used is the concept of equal groups or groups of. These prompts may help.
- Are there groups of the same size? (If so, using multiplication or division facts will be more efficient than repeated addition.)
- Are equal groups being joined? (multiplication)
- Is a group being shared or separated into equal groups? (division)
Drawing, acting or using materials may also help students to decide.
- Once the equation is written down students can then decide which strategy they might use to find the answer.
- Remind students to check their answer.
- Does it answer the question? For example, if the question asks, “How many biscuits are on each plate?” Does the answer to the division equation include the word ‘biscuits’?
- Does it make sense? For whole numbers, the answer to a multiplication problem will be either the same or bigger, and the answer to a division problem will be either the same or smaller.
- Go to Activity 2 page 151 in the Student Resource Book to show the process, which you could use to support students’ problem solving in this chapter.
Adding, subtracting, multiplying or dividing page 155
- Understand whether addition, subtraction, multiplication or division is needed to solve a problem.
- Use the appropriate operation or combination of operations to solve a problem.
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Teacher notes
- Most real-life problems do not come neatly packaged as an equation, therefore it is very important that students understand the meaning associated with each operation, and are given the opportunity to practise so that they gain confidence when applying mathematics in realistic situations. Students will also learn that some problems require a combination of operations to be solved.
- It is sometimes helpful to have students solve problems with a partner or in a small group to support students with literacy challenges, and because when working collaboratively students tend to ‘struggle’ for longer and be able successfully to solve more challenging problems.
