Solve: 9×7×3/9 - Multiplication with Fractions

Q: Why do I put 9 and 7 in the numerator?

When multiplying whole numbers by fractions, every whole number becomes part of the numerator. Think of 9 as $ \frac{9}{1} $ and 7 as $ \frac{7}{1} $.

Q: How do I know which numbers can cancel?

Look for identical numbers in the numerator and denominator. In this problem, 9 appears in both places, so they cancel out completely, leaving $ 7\times3 $.

Q: Can I cancel before multiplying everything out?

Yes, that's actually better! Cancel common factors first: $ 9\times7\times\frac{3}{9} $ becomes $ 7\times3 = 21 $ immediately.

Q: Why isn't the answer 3 or 7?

After canceling the 9's, you still have $ 7\times3 $ left to multiply. Don't stop at just one number - complete the multiplication to get 21!

Fraction Multiplication with Simplification

$9\times7\times\frac{3}{9}=$

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Step-by-step video solution

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00:00 Solve

00:03 We'll make sure to multiply by the numerator and keep the denominator

00:07 We'll reduce what we can

00:13 And this is the solution to the question

Step-by-step written solution

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Understand the problem

$9\times7\times\frac{3}{9}=$

Step-by-step solution

Given that in the exercise there is only multiplication, we add 9 and 7 to the numerator of the fraction as follows:

$\frac{9\times7\times3}{9}=$

We simplify the 9 in the numerator and denominator, and obtain:

$7\times3=21$

Final Answer

$21$

Key Points to Remember

Essential concepts to master this topic

Rule: Place whole numbers in numerator when multiplying with fractions
Technique: Simplify by canceling common factors: $\frac{9\times7\times3}{9} = 7\times3 = 21$
Check: Verify cancellation is correct: 9 cancels completely leaving $7\times3 = 21$ ✓

Common Mistakes

Avoid these frequent errors

Trying to add numbers instead of multiplying
Don't add 9 + 7 + 3/9 = 19.33! Multiplication means all numbers work together as one operation. Always multiply in order: $9\times7\times\frac{3}{9} = \frac{9\times7\times3}{9} = 21$ .

Practice Quiz

Test your knowledge with interactive questions

$$ 13+5+5= $$ ?

FAQ

Everything you need to know about this question

Why do I put 9 and 7 in the numerator?

When multiplying whole numbers by fractions, every whole number becomes part of the numerator. Think of 9 as $\frac{9}{1}$ and 7 as $\frac{7}{1}$ .

How do I know which numbers can cancel?

Look for identical numbers in the numerator and denominator. In this problem, 9 appears in both places, so they cancel out completely, leaving $7\times3$ .

What if there's nothing to cancel?

No problem! Just multiply all the numerators together and divide by the denominator. Canceling just makes the math easier when possible.

Can I cancel before multiplying everything out?

Yes, that's actually better! Cancel common factors first: $9\times7\times\frac{3}{9}$ becomes $7\times3 = 21$ immediately.

Why isn't the answer 3 or 7?

After canceling the 9's, you still have $7\times3$ left to multiply. Don't stop at just one number - complete the multiplication to get 21!

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