Lesson 7 — Activity 1: Introduction to Algebra

Getting Ready

In the previous lesson in this theme, you reviewed patterns in our everyday lives. In the lessons that follow in this theme, you will look more closely at the patterns in formulas and equations. These patterns are called algebra. Algebra is the language through which we describe patterns.

Try This:

Answer the equation below:

x + 5 = 10

To answer this question, you need to think about what number (x) is. You know that 5 + 5 = 10, therefore, x = 5! You have just answered an algebraic equation!

One of the most interesting parts of any math course is learning about patterns. Patterns are all around us. When we are making a recipe and want to make a double batch or even a triple batch, we are making a pattern.

One way to explain patterns in math is to use algebra. This is simply a way to represent a pattern. Think of it as a shorthand, of sorts. As opposed to having to do something over and over again, algebra gives you a simple way to express that repetitive process.

Algebra is about finding the unknown, or it is about putting real-life problems into equations and then solving them.

For example, look at the problem below:

A clown was carrying a handful of balloons. Along came the wind and blew 8 away, leaving him with only 9. How many did he start with?

In algebra, this problem would then be converted to:

x – 8 = 9

The x replaces the unknown that we are trying to find out (how many he started with). We know the wind blew 8 away (so we subtract 8), and we know that the man was left with 9 balloons (the answer to the problem).

Remember, in algebra x seems to be the favourite letter to substitute for the unknown, but you can use any letter of the alphabet you want!

There are two terms that you need to know when you are working with algebra:

variable and constant

  • A variable (also called the unknown) is simply a symbol that is used to represent an unknown number. In algebra, we use any of the letters in the alphabet for variables.

For example, if we have the equation 2x, the variable is x.

Equations can have more than one variable. For example, you could be given the equation 6z + y = 16. Both z and y are variables.

  • A constant is a set number in an equation.

For example, in the equation 2x, the constant is 2.


Try this!

Solve the simple algebraic equations below.

5 + x = 10

6 + x = 9

10 – x = 5

9 – x = 3

5 + 5 = 10

6 + 3 = 9

10 – 5 = 5

9 – 6 = 3

Digging Deeper

Click on the Play button below to watch a video on algebra basics.