How to Add, Subtract, Multiply, and Divide Fractions: A Math Review

Adding and Subtracting Fractions

• 🎯 To add or subtract fractions, you must first find common denominators.
• 💡 An example demonstrates multiplying the first fraction by the second fraction's denominator and vice-versa to achieve this.
• ✅ For 2/3 + 3/4, common denominators result in 8/12 + 9/12, yielding an improper fraction of 17/12, which converts to the mixed number 1 and 5/12.
• ⚠️ For 5/6 - 2/5, common denominators lead to 25/30 - 12/30, resulting in 13/30.

Multiplying Fractions

• 🚀 Multiplying fractions involves multiplying across the numerators and denominators.
• 🧩 For 3/4 * 5/8, the result is 15/32.
• 🔍 Before multiplying, it's often beneficial to simplify fractions by canceling out common factors between numerators and denominators to make calculations easier.
• ✨ In the example 3/7 * 4/21, simplifying by canceling a 7 and a 4 leaves 3/8.

Dividing Fractions

• ➗ To divide fractions, use the keep, change, flip method: keep the first fraction, change division to multiplication, and flip the second fraction.
• ➡️ For 3/5 ÷ 2/7, this becomes 3/5 * 7/2, resulting in 21/10.
• 🔢 The improper fraction 21/10 can be converted to the mixed number 2 and 1/10.
• ➗ For 1/6 ÷ 8/15, applying keep, change, flip results in 1/6 * 15/8. Simplifying before multiplying (canceling 3 from 6 and 15, and 2 from 6 and 8) yields 1/4.