Subtract Fractions with Different Demoninators trick - mentally minus fractions instantly! | Summary and Q&A

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February 12, 2014
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tecmath
Subtract Fractions with Different Demoninators trick - mentally minus fractions instantly!

TL;DR

Learn a simple trick to subtract fractions without the need for complex calculations or common denominators.

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Q: How can I subtract fractions with different denominators quickly?

To subtract fractions, multiply the denominators to get the bottom number, then multiply the numerators by the opposite denominators and subtract the products.

Q: Is it important to follow a specific order when multiplying the numerators and denominators?

Yes, it is crucial to start with the numerator of the left fraction and the denominator of the right fraction, and then vice versa. This order ensures the correct subtraction of the products.

Q: Can we simplify the resulting fraction?

Yes, after subtracting, you can simplify the fraction by finding a common factor for the numerator and denominator and dividing them by it.

Q: How can this method be applied to mixed numbers?

The method works for mixed numbers as well. Convert the mixed numbers to improper fractions, subtract using the same procedure, and simplify if necessary.

Summary & Key Takeaways

• The video demonstrates a quick method for subtracting fractions with different denominators without extensive working out.

• The bottom number (denominator) is obtained by multiplying the denominators of the fractions.

• The top number (numerator) is found by multiplying the numerator of the left fraction by the denominator of the right fraction, and vice versa, and then subtracting the products.