Mathematics 7

# Surf for More Math

## Lesson 3 - Solve Problems by Guessing and Testing

To encourage students to have fun on the Web while learning about Solve Problems Using Guessing and Testing, here are some games and interactive activities they can do on their own or in pairs.

### Goal

Use guess and test and a table to solve measurement problems.

### Builds Upon

Student Book pages 394-397

### Instructions for Use

Volume and Surface Area is a complex program that prompts students to guess and test surface area and volume.

To use Volume and Surface Area remember to construct the shape from back to front, or from bottom to top. Select and drag cubes from the column, and place them on the work area. Click on the work area to drop the shape. Using the white arrow icon, from the top row, move the cubes to any location.

Click on the net icon to view the shapes from different perspectives. A separate pop-up window lets students rotate the shapes by moving the sliders.

To change the colour of a cube, click on the rainbow icon, and a pop-up window displays colours. Click on a colour in the colour palette, and then click on the cube in the workspace.

To move a cube behind another, click on the icon with 3-diagonal boxes having the blue box least prominent. To move a cube in front of another, click on the icon with 3-diagonal boxes having the blue box most prominent.

To erase a single shape, click the eraser icon and click on the shape to be erased. To erase all shapes, click the eraser icon and click twice on the work area.

Have students build shapes block by block to guess the surface area and volume.

Three-Dimensional Box lets students observe how to change sides of a rectangular prism to affect its volume.

To use Three-Dimensional Box, drag the cursor in the top left quadrant over the rectangle. Dotted lines illustrate where the paper's corners will be cut. Click the "Cut and Fold" button, and the rectangle folds into a prism.