1. What is Cross Multiplication?

Cross multiplication is a mathematical technique used to solve proportions or verify if two ratios are equal. It's based on the principle that for two equal fractions, the product of the numerator of one and the denominator of the other will be equal.

2. How Does Cross Multiplication Work?

The cross multiplication formula:

Explanation: When two fractions are equal, multiplying the numerator of the first fraction by the denominator of the second fraction equals the denominator of the first fraction multiplied by the numerator of the second fraction.

3. Applications of Cross Multiplication

Details: Cross multiplication is commonly used in:

• Solving proportion problems
• Verifying if two ratios are equivalent
• Solving for unknown variables in equations
• Scaling recipes or measurements
• Calculating percentages and rates

4. Using the Calculator

Tips: Enter values for a, b, c, and d in the proportion a/d = b/c. The calculator will verify if the cross products are equal (a×c = b×d) and show the results.

5. Frequently Asked Questions (FAQ)

Q1: What does it mean if the cross products are equal?
A: If a×c = b×d, then the original proportion a/d = b/c is true and the two ratios are equivalent.

Q2: Can cross multiplication be used to solve for an unknown?
A: Yes, if three values are known, you can solve for the fourth unknown value in the proportion.

Q3: Does cross multiplication work with decimal numbers?
A: Yes, the calculator handles both whole numbers and decimal values.

Q4: What's the difference between cross multiplication and regular multiplication?
A: Cross multiplication specifically refers to multiplying across an equality of two ratios, while regular multiplication is a general arithmetic operation.

Q5: Can I use this for complex fractions?
A: This calculator works with simple numerical proportions. For complex fractions with variables, algebraic manipulation may be needed.