Change Around
Problem
Here is another triangular shape made from arranging circles.
Move just three of the circles so that the triangle faces in the opposite direction.
You could use this interactivity to try out your ideas:
Student Solutions
"This was fun," we heard from many people who moved the circles around as they tried to find out how to rebuild the triangle so it faced in the opposite direction. Gerrit did very well to put into words what you needed to do:
"To change the triangle's direction with only three moves, move the outside bottom row balls to the second row from the top, and move the top ball to the bottom."
Easy when you know how!
Teachers' Resources
Change Around
Here is another triangular shape made from arranging circles.
Move just three of the circles so that the triangle faces in the opposite direction.
You could use this interactivity to try out your ideas:
Possible approach
This activity can be approached several ways in the classroom. Each child can be given a set of ten counters, coins or discs and asked to set up the triangle and then physically move the objects. A more abstract approach is to ask the children to draw the shape and visualise what changes can be made and then try them out. A third alternative is to use the interactivity provided and allow the children to move the red circles to form the new triangle.
Key questions