Assign each student a partner. Give each partner team a recipe. Each partner team is to calculate the recipe for a number of servings other than the one indicated on the original recipe. Students may increase or decrease the original recipe (for example, they may calculate for 6 servings instead of 9, or for 2 servings instead of 8). Set a time limit. The partner team who has the most correct "fraction conversions" at the end of the time limit wins. (A small prize for the winning team is appropriate.)

Note: Each team should have recipes with approximately the same number of ingredients and approximately the same skill level. Be prepared to award several small prizes, for teams may tie.