Blasting bugs
This is a level 4 geometry activity from the Figure It Out series. It is focused on giving directions using grid references. A PDF of the student activity is included.
About this resource
Figure It Out is a series of 80 books published between 1999 and 2009 to support teaching and learning in New Zealand classrooms.
This resource provides the teachers’ notes and answers for one activity from the Figure It Out series. A printable PDF of the student activity can be downloaded from the materials that come with this resource.
Specific learning outcomes:
- Give directions using grid references.
Blasting bugs
Achievement objectives
GM4-7: Communicate and interpret locations and directions, using compass directions, distances, and grid references.
Required materials
- Figure It Out, Level 4, Geometry, Book One, "Blasting bugs", page 24
- square grid paper
- classmate
See Materials that come with this resource to download:
- Blasting bugs activity (.pdf)
Activity
No matter where a person stands (except at the poles), every other point on the face of the earth is either north or south of them or west or east of them. In other words, from their perspective, the world can be divided into 4 regions defined by direction: NE, NW, SE, and SW. These are known as the 4 quadrants of the compass.
The same concept is used in this activity. If a student guesses that the BB bug is in square D3 when it is really hiding in square G1, their classmate would tell them that the bug is in the quadrant SE of D3 (the area that is to the south and the east of D3).
Note that if a student's guess is in the correct north-south or east-west line, their classmate will respond by naming the correct direction (N, S, E, or W), not by naming a quadrant.
It is probably best not to try and link this grid too closely with the system of x and y axes that are the standard for algebraic functions. The two systems have these important differences that are likely to confuse students:
Standard x and y axes |
Blasting bugs grid |
|---|---|
The grid reference defines a point. |
The grid reference defines a cell. |
The quadrants are defined from a fixed point ([ 0,0 ] the origin). |
The quadrant is redefined after every move. |
The axes are labelled with integers. |
The axes are labelled using the alphabet and whole numbers. |
You could also discuss these ideas with your students:
- Although there is a northern hemisphere and a southern hemisphere, there is no true western or eastern hemisphere (these terms are, however, sometimes used). Why is this? What do we mean when we talk about "the West" and "the East"?
- Although NE (for example) is used in this activity to define a quadrant, it is also used as a precise compass direction. What does this mean, and what are the other directions marked on a traditional compass (for example, SSW)?
- What is the significance and history of the line of longitude that passes through Greenwich?
A game that involves using compass directions.
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