# Surf for More Math

## Lesson 3 - Patterns that Grow and Shrink

To encourage students to have fun on the Web while learning about Patterns that Grow and Shrink, here are some games and interactive activities they can do on their own or in pairs.

### Goals

Relate growing and shrinking patterns to repeated addition and subtraction.

Transfer a pattern to a t-chart.

### Instructions for Use

I Know That lets students skip count using repeated addition and subtraction.

To use I Know That, enter your registration information and click ‘Submit’, or click on ‘Maybe Later’ in the bottom middle of the screen to proceed to the activity. Click on the "Give Me a Problem" button on the scratch pad. Problems are presented on the PDA screen.

Use the counters (below the trashcan) to make sets and practice skip counting. Click and drag the counters in or out of the counter box, the corresponding number is displayed in the "How many?" box.

Counters are shown in the counter box (the main workspace) along with the total number in the set. To change the number of counters in the box, drag numbers in or out of the counter box; or click on one of the numbers above the counter box.

To use the Counter group, (below the counters), click on a number to select the counter group to use in skip counting. When students click on one of the numbers in the counter group, the counter group changes and the corresponding number sequence is displayed.

Click on one of the numbers (the line above the trashcan) to change the set of counters in the counter box, and the number displayed in the "How many?" box.

Click the "New" button to clear the scratch pad and select a different counter.

To remove counters from the counter box, click and drag them into the trashcan.

Interactive Calculator allows students to make growing and shrinking patterns using the calculator.

To use Interactive Calculator, start by pressing a number on the interactive calculator. This number will appear in the calculator window. Press the "+" button on the calculator, and then the same number over and over. Press the "=" button on the calculator. The growing pattern is shaded on the hundreds chart.

To make a shrinking pattern, start by inputting a large number. Press the "-" button on the calculator, and then the same number over and over. Press the "=" button on the calculator. The shrinking pattern is shaded on the hundreds chart.