## CHAPTER 1: NUMBER RELATIONSHIPS

**Lesson 6: Determining Common Mulitiples **

Use these interactive activities to encourage students to have fun on the Web while learning about number relationships. Students can try these activities on their own or in pairs.

**Goal**

Identify multiples, common multiples, and least common multiples of whole numbers.

**Builds Upon**

Student Book pages 22–25

**Instructions for Use**

**Factor Tree** allows students to find the factors of common and least common multiples of numbers.

To use Factor Tree, consider what number could be a factor of the least common multiple (LCM) shown in the yellow box near the top of the screen. Type your number in the blank white box below and hit “Enter”. If your number is a factor, the other factor of the LCM will appear in the box to its right. If either of these factors is a multiple of other factors a new pair of boxes to be filled in will appear below. If a number you type is not a factor an error message will appear and you will need to correct your number. When all the factors have been found they are displayed at the bottom of the screen. You can then click on “New Problem” to play again. To vary the game you can also choose between “One” and “Two” trees and between “Computer” and “User” generated numbers by clicking on the respective buttons at the bottom.

**Least Common Multiple ** allows students to match least common multiples to pair of factors.

To use Least Common Multiple, click on “Start” and then compare the 6 least common multiples at left with the 6 pairs of factors at the bottom of the screen. When you think you have a match click and drag a pair of factors to the empty box across from the LCM you have chosen. When all the empty boxes are filled, click on “Check” to find your score, and then on “Again” to play the same numbers again, or on “Main” and then “Load new” to play a new set of numbers. Clicking on “Swap cards” in the main menu alternates the positions of the LCM and factor cards.