Number & Algebra
Chapter 2 | Adding and subtracting using place value partitioning
Teacher Resource Sheets
Getting Started
Draco (Getting started 2)
(Getting starting before page 75 to revise the concept of tens numbers.)
- Before beginning this activity, you could give groups of students a large quantity of objects to count as quickly as possible. Discuss the ways they found to count their pile of objects quickly and accurately and how they know their count is correct.
- If students have not already done so, demonstrate how all students in a group can make piles of ten and use these piles efficiently to find the total number of objects.
Adding using place value partitioning
Splitting one number into tens and ones (Teacher Resource Sheet 4)
(Further discussion following the teaching section page 78. The first sheet uses tens frames, the second shows the same problem solved using a number line.)
- Encourage students to use tens frames or other place value materials to explain their strategy. It is important that they also develop ways to record their thinking as equations, on a number line, or as a diagram. Some ideas for recording are given in the Student Resource Book.
Rolling over the ten (Teacher Resource Sheet 5)
(Further discussion following the teaching section page 80, displaying tens frames with a further example of rolling over the ten for discussion.)
- Students could use different place value materials such as an abacus, or a hundreds chart to explain this strategy.
How much? (Teacher Resource Sheet 6)
(Further discussion prior to Activity 2 on page 81 displaying a word problem that is solved using money to represent place value.)
- Using different types of place value material challenges students’ understanding of a strategy. Students could record each step of Hemi’s explanation on a number line as it is discussed.
Subtracting using place value partitioning
Taking away the tens then the ones (Teacher Resource Sheet 7)
(Further discussion following the teaching section on page 82 displaying tens frames to show subtracting using place value by first taking away the tens and then the ones.)
- When students use equations to record steps in their strategy, encourage them to begin each equation on a different line, which avoids students inadvertently using the equals sign when the sides do not balance.
- Emphasise the direction of the jump on the number line when subtracting and encourage students to notice that numbers get smaller with each jump.
Jumping again (Teacher Resource Sheet 8)
(Further discussion following Jess’s example on page 83 displaying two number lines which could be used to help students understand how to make a second jump to roll back through a ten on a number line.)
- When students record jumps as equations, encourage them to begin each equation on a different line. This avoids students inadvertently using the equals sign when the sides do not balance
