About This Book

This math book was made in 2013. A group called MMAISE made it in Salt Lake City, USA.

Anyone can use this book for free. You can share it, change it, and give it to others. This is called an "open" book.

Table of Contents

This book has a Table of Contents. A Table of Contents is a list. It shows what is inside the book and what page each part is on.

Chapter 1: Probability, Percent, and Rational Numbers

This chapter takes about 3 to 4 weeks to learn. It has three big sections.

Section 1.1 is about chance. "Chance" means how likely something is to happen. Students learn to guess what might happen using math. This is called probability.

Section 1.2 is about three ways to show a part of something: fractions, decimals, and percents. Students learn how these three are all connected. They also learn to put numbers in order from smallest to biggest.

Section 1.3 is about solving problems with percents. This includes discounts (money off a price), interest (extra money you earn or pay), taxes, tips, and things going up or down by a percent.

What Students Will Learn

Students will learn to:

• Change a fraction into a decimal.
• Solve real-life math problems using fractions, decimals, and percents.
• Understand that probability is a number between 0 and 1. A number near 0 means something is not likely to happen. A number near 1 means it is very likely to happen. A number near ½ means it could go either way.
• Test out chance by trying something many times, like rolling a die, and see what really happens.
• Solve harder problems that use more than one step, using fractions and decimals.

What This Chapter Is About

This chapter starts with probability. Probability helps students practice using whole numbers and fractions. Students will learn to count outcomes (an outcome is one possible result). They will also learn the difference between:

• Theoretical probability — what you expect to happen using math.
• Experimental probability — what really happens when you test it out.

Starting the year with probability helps students think about math in the real world. It also helps the class talk and work together.

Next, students review fractions, percents, and decimals from past grades. They learn that all three are ways to show a part of one whole thing. Students also learn to compare and order fractions, even ones that are negative (less than zero).

The chapter ends by solving percent and fraction problems. This includes discounts, interest, taxes, tips, and percents going up or down.

Important Words

• Chance – how likely something is to happen
• Decimal – a number with a dot, like 0.5
• Experimental probability – what really happens when you test something
• Fraction – a part of a whole, like 1/2
• Frequency – how many times something happens
• Outcome – one possible result
• Percent – a part of 100, like 50%
• Probability – the chance that something will happen
• Ratio – comparing two numbers
• Theoretical probability – what you expect to happen, using math

What Students Already Know

Before this chapter, students learned about ratios. A ratio compares one thing to another. In this chapter, students only compare a part to the whole thing. Probability, fractions, decimals, and percents all work this way.

Students already know how to add, subtract, multiply, and divide fractions and decimals. They have used number lines and simple pictures to show fractions, percents, and decimals.

Last year, students put both positive and negative numbers on a number line. But they did not yet do math problems with negative numbers. They will learn that in Chapter 2.

What Comes Next

After this chapter, students will study probability again in Chapter 7. They will use what they learn here about chance, and about theoretical and experimental probability, to do even more with it later.