Read the Headline Story to the students. Encourage them to make a table to list all the possible numbers of intersections.
There are 10 streets in our small town. Some streets run from north to south. The rest of the streets run from east to west.
North/South | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
East/West | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 |
Intersections | 16 | 21 | 24 | 25 | 24 | 21 | 16 | 9 |