Arithmetic Operations with Rational Numbers

Study Notes

Arithmetic Operations with Rational Numbers

The operation of combining two numbers is known as arithmetic operations or calculations. These operations involve addition, subtraction, multiplication, and division. In mathematics, rational numbers form a subset of real numbers and can represent any value that can be expressed as a ratio of integers or fractions, where one number is divided by another.

Addition of Rational Numbers

Adding rational numbers involves adding their numerators while keeping the denominators equal. For example, if we have two fractions: \(\frac{2}{5}+\frac{3}{5} = \frac{5}{5}\), which simplifies to 1. Similarly, if we have two mixed numbers: \(1+\frac{3}{4}=\frac{7}{4}\).

Subtraction of Rational Numbers

Subtracting rational numbers follows similar rules, involving the subtraction of their numerators while maintaining equivalent denominations. However, the order matters - if you're subtracting a larger fraction from a smaller one, you need to flip it: \([\frac{5}{8}-\frac{3}{4}] + [\frac{3}{4}-\frac{5}{8}]=0\).

Multiplication of Rational Numbers

Multiplication of rational numbers involves the product of the numerators and denominators. For example, \(\frac{2}{3} \times \frac{3}{4} = \frac{3}{4} \times \frac{4}{5} = \frac{1}{2}\). This rule also applies to mixed numbers: \(2 \times \frac{3}{4} = 3\).

Division of Rational Numbers

Division of rational numbers follows the rule of reversing the multiplication operation. For example, \(\frac{2}{3} \div \frac{3}{4} = \frac{2}{3} \times \frac{4}{3} = \frac{4}{3}\). The same rule applies to mixed numbers: \(2 \div \frac{3}{4} = \frac{4}{3}\).

Adding and Subtracting Rational Numbers with Decimals

Adding and subtracting rational numbers with decimals follows the same rules as for whole numbers, but with an additional step to ensure the decimals match. For example, \(0.3 - 0.25 = 0.3 - 0.25 = 0.05\).

Adding and Subtracting Rational Numbers with Fractions

Adding and subtracting rational numbers with fractions follows the same rules as for whole numbers, but with an additional step to ensure the denominators match. For example, \(\frac{2}{3} + \frac{1}{4} = \frac{8}{12} + \frac{3}{12} = \frac{11}{12}\).

Multiplication of Rational Numbers with Decimals

Multiplication of rational numbers with decimals follows the same rules as for whole numbers. For example, \(0.5 \times 1.3 = 0.65\).

Division of Rational Numbers with Decimals

Division of rational numbers with decimals follows the same rules as for whole numbers. For example, \(0.5 \div 1.3 = 0.3846153846153846\).

Division of Rational Numbers with Fractions

Division of rational numbers with fractions follows the same rules as for whole numbers. For example, \(\frac{2}{3} \div \frac{1}{4} = \frac{2}{3} \times \frac{4}{1} = \frac{8}{3}\).

Adding and Subtracting Rational Numbers with Different Denominators

Adding and subtracting rational numbers with different denominators requires finding a common denominator. For example, \(\frac{2}{3} + \frac{3}{5} = \frac{6}{15}+\frac{9}{15} = \frac{15}{15}=\frac{1}{1}\).

Multiplying and Dividing Rational Numbers with Different Denominators

Multiplying and dividing rational numbers with different denominators requires finding a common denominator. For example, \(\frac{2}{3} \times \frac{3}{4} = \frac{6}{12} \div \frac{8}{12} = \frac{1}{4}\).

In conclusion, arithmetic operations with rational numbers involve following the same rules as for whole numbers, but with additional steps to ensure the denominators match when necessary. These operations are essential for solving various mathematical problems and understanding the relationships between different numbers.

Description

Learn about addition, subtraction, multiplication, and division of rational numbers including fractions and mixed numbers. Understand the rules for combining rational numbers with decimals and fractions, as well as dealing with different denominators. Enhance your understanding of arithmetic calculations involving rational numbers.