Geometry and Spatial Sense, Grades 4 to 6 - EduGains

• “What strategy did you use to decide where the line would go?”
• “Did you change your strategy? Why?”
• “Did you use the grid as part of your strategy?”
When students have had a chance to play the game, provide each pair with markers and a sheet of
chart paper or large newsprint. Ask students to record their strategies on the paper to show how
they chose the location for their line of reflection.
Make a note of pairs who might share their strategies during the Reflecting and Connecting part
of the lesson. Include groups whose methods varied in their degree of efficiency (e.g., using
guess and check, finding a cell halfway between the edge of the shape and the target, finding
the cell halfway between the centre of the shape and centre of the target).
REFLECTING AND CONNECTING
Once students have had the opportunity to play the game and record their strategies, bring
them together to share their ideas. Try to order the presentations so that students observe
inefficient strategies (e.g., picking at random) first, followed by more efficient methods.
As students explain their ideas, ask questions to help them to describe their strategies:
• ”How does your strategy work?”
• “Did you change your original strategy? Why?”
• ”Did you use the grid in your strategy? How?”
Following the presentations, ask students to observe the work that has been posted and to
consider the efficiency of the various strategies. Ask:
• “Which strategy, in your opinion, is an efficient strategy for finding the line of reflection?”
• “How would you explain the strategy to someone who has never used it?”
Avoid commenting that some strategies are better than others – students need to determine
for themselves which strategies are meaningful and efficient, and which ones they can make
sense of and use.
Refer to students’ work to emphasize geometric ideas:
• A grid system can be helpful in locating specific objects.
• A reflection is the same distance away from the line of reflection as the original object.
Provide for students an opportunity to play additional or related games to try new strategies.
ADAPTATIONS/EXTENSIONS
Those students having difficulty with the concept may benefit from working on an enlarged
copy of the game showing one shape and the target.
Students could use plain grids, pattern blocks instead of shapes, and a piece of string as the
target. They could reflect the pattern blocks onto the target from different locations.
Grade 4 Learning Activity: Movement – hit the Target 121