Purpose

The purpose of this activity is to engage students in logical thinking and simple addition and subtraction.

Achievement Objectives

NA1-5: Generalise that the next counting number gives the result of adding one object to a set and that counting the number of objects in a set tells how many.

Description of Mathematics

In readiness for this problem, the students should have familiarity with each of the following components of mathematics. The problem may be solved with different combinations of these components.

- Counting one to one
- Counting on
- Equal sharing
- Partitioning

This activity may be carried out with guidance, or by allowing the student to follow their own method of solution. The approach should be chosen in sympathy with students’ skills and depth of understanding.

Activity

Ari, Ben, Cam, Dan and Eva are counting their card collections.

Ari has 21 cards. Cam has 2 more than Ari. Ben has 3 fewer than Cam and 1 more than Dan who has 3 fewer than Eva.

How many cards does Eva have?

Put the children’s names in order from the person with the fewest cards to the person with the most.

**Note to teacher:** This activity requires materials for illustration. Playing cards could be used, or could be represented by counting materials such as counters.

- The student is able to use images and/or objects to represent a problem and find a solution.

- The student is able to solve a problem using sharing and other strategies, to find unknown addends.

Printed from https://nzmaths.co.nz/content/card-collections at 4:19pm on the 11th July 2020