Number & Algebra
Chapter 1 | Adding and subtracting using a range of strategies
Teacher Resource Sheets
Adding and subtracting using reversibility (page 30)
How far away are you? (Getting started 1)
(This sheet could be used to introduce the unit and encourage students to think about where addition and subtraction is used to solve real-life problems.)
This displays the Getting started on page 27.
You could find a suitable sign post close to the school and take a photo of it for students to work with. Or you could use this to help with calculating distances between places.
https://www.aa.co.nz/travel/time-and-distance-calculator/
Students could plot a journey through the country adding total distance and time for the trip. This is also good for learning about geography.
This sheet could be used to aid understanding of reversibility and assist students to write the equation for a problem and decide whether to add or subtract. This sheet could be used to give further examples prior to Activity 1 on page 31 or as additional practice.
This displays some problems and an empty number strip for each.
If you can display this on a write on surface, such as a smart board or a pdf writer, you can ask students to come and fill in the number strip and then write the number sentence for each one.
Ask students for all the different ways that the number strip can be represented by an equation.
Should I be rewritten? (Teacher Resource Sheet 2)
(This could be used once students have done some of Activity 1 on page 31 of the Student Resource Book and used to generate a discussion about when reversibility is an efficient strategy.)
This displays some addition and subtraction equations and students are asked to decide whether turning would make them easier to solve.
Adding using near doubles (page 34) & Adding & subtracting using complementary numbers (page 35)
Double me up (Teacher Resource Sheet 3)
(This sheet could be used prior to the teaching on page 34.)
This displays some numbers and asks students to pair up the numbers that are near doubles.
If you display this onto a write on surface lines can be drawn between the near doubles.
Students are then asked to add the numbers they have matched.
Give me a complement (Teacher Resource Sheet 4)
(This sheet could be used alongside the teaching on page 35.)
This displays some numbers and asks students to pair up the complements.
If you display this onto a write on surface lines can be drawn between the near doubles.
Students are then asked to add the numbers they have matched.
Choosing an efficient strategy for addition & subtraction (page 36)
Which way is most efficient? (Teacher Resource Sheet 5)
(This sheet could be used in conjunction with Activity 4 on page 36.)
This displays a sheet with one addition and one subtraction problem and asks students to find the answer using an efficient strategy.
Encourage students to argue that their way is best.
You could take a vote at the end.
And the answer is… (Teacher Resource Sheet 6)
(This sheet could be used in conjunction with Activity 4 on page 36.)
This displays some numbers and asks students to think of equations that would be best solved using these strategies.
place value partitioning
tidy numbers
doubles
