In the previous lesson we learned about the importance of carrying out number operations in the proper order. Let's take a quick review.

Click the “Submit” button after selecting your answer.

Now, let’s move on with today’s lesson.

There are several addition and multiplication properties of numbers that we will use when we work with expressions and equations.

We can show the effect of these properties with this rocket race game.

Rocket A has a thrust set at 5. Rocket B has a base thrust of 5 that is modified according to a particular number property.

Select a modifier by clicking on the radio button next to it. Begin the rocket race by clicking on the “Start” button. The rocket with the greater thrust will win.

Now, select the “Additive Identity” modifier and click on the “Start” button.

Which of the following statements is true about the rocket race? Click the “Submit” button after selecting your answer.

The additive identity property states that any number plus zero equals that number.

The thrust of rocket B was 5 + 0 = 0, so it tied with Rocket A in the race.

Now, select the “Additive Inverse” modifier and click on the “Start” button.

Which of the following statements is true about the rocket race? Click the “Submit” button after selecting your answer.

The additive inverse property states that any number plus its additive inverse, or opposite, is equal to zero.

Rocket B lost the race because its thrust was 5 + (-5) = 0.

Now, select the “Multiplicative Identity” modifier and click on the “Start” button.

Which of the following statements is true about the rocket race? Click the “Submit” button after selecting your answer.

The multiplicative identity property states that any number multiplied times one is equal to that number.

The thrust of Rocket <EQUATION> was <EQUATION>. Therefore, the two rockets tied.

Now, select the “Multiplicative Zero” modifier and click on the “Start” button.

Which of the following statements is true about the rocket race? Click the “Submit” button after selecting your answer.

The multiplicative property of zero states that any number times zero is equal to zero.

Rocket <EQUATION> lost the race because its thrust was <EQUATION>.

Now, select the “Multiplicative Inverse” modifier and click on the “Start” button.

Which of the following statements is true about the rocket race? Click the “Submit” button after selecting your answer.

The multiplicative inverse property states that two numbers whose product is one are multiplicative inverses, or reciprocals, of each other.

Thrust of rocket <EQUATION> was <EQUATION>. Rocket <EQUATION> had a greater thrust, so it won the race.

Here’s a list of the properties are we learned today, along with some examples of these properties.

In the box next to each example, enter the number of the property that applies.

After entering your answers, click the “Submit” button to show the correct answer next to each box.

Copyright 2006 The Regents of the University of California and Monterey Institute for Technology and Education