  # Surf for More Math

## Lesson 4 - Subtracting Fractions with Models

To encourage students to have fun on the Web while learning about Subtracting Fractions with Models, here are some games and interactive activities they can do on their own or in pairs.

### Goal

Subtract fractions less than 1 using a part of a model.

### Builds Upon

Student Book pages 316-319

### Instructions for Use

Fraction Bars helps students subtract fractions within a whole using fraction bars.

A fraction bar appears when the applet opens. To use Fraction Bars, determine the size of the denominator by clicking on the up or down arrows beside the fraction bar. Click the "fdrp" button. This button allows students to see the sections on the fraction bar as fractions, decimals, ratios or percentage - click the "f" for fraction display. Determine the size of the numerator by clicking on the sections inside the fraction bar - they change colour from green to yellow. Click on the bar button to make up to 5 new fractions bars. Click the 'Reset' button to start again.

Using several bars together at one time allows students to manipulate and compare the size of the sections in the bars.

Subtracting Unlike Fractions prompts students to subtract fractions using a model.

To use Subtracting Unlike Fractions, click the "New Problem" button. Input the common denominator of both fractions. Find the equivalent numerators. Press 'Enter' to find the difference.   