# Making Flubber

Purpose

The purpose of this activity is to engage students in using fractions, proportions and percentages to solve a problem.

Achievement Objectives
NA3-5: Know fractions and percentages in everyday use.
Description of Mathematics

The background knowledge and skills that should be established before and/or during this activity are outlined in the diagram below:

Click to show example questions for each heading

This activity may be carried out with step by step guidance, or by allowing the student to follow their own method of solution. The approach should be chosen in sympathy with students' skills and depth of understanding.

Activity

A class wants to make Flubber.

Their teacher gives them a recipe which uses 4 1/4 cups of water, 4 cups of PVA glue and 4 teaspoons of Borax. She says that they have all the ingredients but only a teaspoon for measuring.

The teacher tells them that Borax makes up 1% of the final mixture, so they should be able to work out how many teaspoons of water and PVA glue to add.

How can the class use this information to work out how many teaspoons in a cup?