Semester 1 Topic 3 Level H

Task Name : Adding and Subtracting Negative Number Stories Task Level : H (Year 7)
Semester : 1 Topic : Directed Numbers VC Strand : Number and Place Value
Web Address :
Equipment Needed : Poster Paper
Victorian Curriculum outcome : Compare, order, add and subtract integers
Task description : Students create eight stories that describe addition and subtraction of positive and negative numbers. Two should describe the addition of positive numbers; two should describe the subtraction of positive numbers; two should describe the addition of negative numbers; and two should describe the subtraction of negative numbers. Each story should contain: the written story; a picture accompanying the story; a number line describing the story; and an algorithm describing the story.
Assessment options : Photograph of poster; digital image.
Teacher notes : Money is a good way to describe these processes. If I have $5 and I gain $10, the algorithm is +5 + +10 = +15 . However, if I have $5 and then gain a bill for $10, this can be thought of as “negative money”, and so the algorithm is  +5 + 10 = 5. Using this analogy, it is easy to see why if I lose a bill (perhaps the issuer recognises that it is a mistake and takes it back), then the algorithm is +5 – 10 = +15… students can see that losing a bill means that you are better off financially.