Learn what rational numbers are and how to represent them. Grade 9 Alberta mathematics curriculum.
Lesson 3.1 of Rational Numbers in Grade 9 Math — Alberta curriculum lessons.
A rational number is any number that can be written as a fraction, where both the numerator and denominator are integers (whole numbers), and the denominator is not zero.
This means:.
Important Concept.
Different Types of Decimals.
Yes, zero is a rational number. It can be written as a fraction:
Both the numerator and denominator are integers, and the denominator is not zero. Even though zero divided by any number is zero, it still follows the rule of rational numbers.
Step-by-Step Process.
Consider the following fractions:
If you calculate each one:
Key Insight.
You can compare rational numbers in different ways:
Important Note
If a question includes both fractions and decimals, you can choose whichever form is easier to work with. It's your choice — either convert the fractions to decimals or the decimals to fractions before comparing. Pick the method that makes the comparison simplest.
Tip. When comparing negative rational numbers, remember: The number closer to zero is greater.For example: -2 > -5Even though 5 is larger in size, -2 is farther right on the number line.
Look at these numbers:
At first, they might look different — some are fractions, some are decimals, and some are whole numbers. But all of them are rational numbers.
Let's see why.
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