Predict the result
What is the slope of the source geoboard’s line?
Count the spaces between its marked endpoints.

Set up the model
Slope is rise divided by run.
Use equally spaced horizontal and vertical units.

Work the example
The source line rises three spaces and runs four spaces to the right.
Write three divided by four.
Its slope is three quarters.
The ratio describes rise per unit of run.

Check the result
Now find the slope of the check geoboard’s line.
Take eight seconds to think before the answer appears.
[Eight-second silent pause to work; the answer remains hidden.]
It rises four spaces while running three spaces.
Its slope is four thirds.

Interpret the result
Count intervals between pegs rather than counting the pegs themselves.
Use the original task and check that your result fits its meaning.