Have seated learners count the number of boys and girls. Write the numbers above each group on board, separated by a colon. Explain that this expression identifies the ratio of boys to girls called to the front. Return to the term on the board and student comments. Have students identify which, if any, ideas identified what a ratio is.
Guide pupils in defining the term.
Divide class into groups. Pupils are to label each ratio. Cut each sandwich into pieces. Conduct a taste test of the preferred ratio. Have each student within the group taste each sandwich and rate it on a scale of one to six.