using rational numbers how to add, subtract, multiply and divide rational numbers
TRANSCRIPT
A rational number is a number that can be written as a simple fraction (i.e. as a ratio).
In general ... So, a rational number looks like this: p / q But q cannot be zero, as that would be dividing by zero.
How to Add, Subtract, Multiply and Divide If the rational number is something simple like 3, or 0.001,
then just use mental arithmetic, or your calculator! But if it is still in the form p / q, then read on to find how to
handle it.
½
A rational number is a fraction, so you could also refer to:
• Adding Fractions,• Subtracting Fractions,
• Multiplying Fractions and
• Dividing Fractions But here I will be showing you those operations in a
more Algebra-like way.You might also like to read Fractions in Algebra.
Multiplication To multiply two rational numbers, just multiply the tops and
bottoms separately, like this:
Division To divide two rational numbers, first flip the second number
over (make it a reciprocal) and then do a multiply like above:
Addition and Subtraction I will cover Addition and Subtraction in one go, as they are
the same method. Before you can add or subtract, the rational numbers should
have the same bottom number (called a Common Denominator).
Be Careful With "Mixed Fractions" You may be tempted to write an Improper Fraction (a fraction
that is "top-heavy", i.e. where the top number is bigger then the bottom number) as a Mixed Fraction:
But for mathematics the "Improper" form (such as 7/4) is actually better.
Because Mixed fractions (such as 1 3/4) can be confusing when you write them down in a formula, as it can look like a multiplication: