Dividing decimals with hundredths | Arithmetic operations | 5th grade | Khan Academy

TL;DR

Learn how to solve a division problem by rewriting it as a fraction and multiplying both the numerator and denominator by the same quantity.

Transcript

Let's see if we can divide 30.24 divided by 0.42. And try pausing the video and solving it on your own before I work through it. So there is a couple of ways you can think about it. We could just write it as 30.24 divided by 0.42. But what do you do now? Well the important realization is, is when you're doing a division problem like this, you will ... Read More

Key Insights

• ✖️ Division problems can be simplified by rewriting them as fractions and multiplying both the numerator and denominator by the same quantity.
• 😥 Multiplying a denominator by a power of 10 can help eliminate decimal points.
• ➗ Dividing digit by digit is an effective strategy for solving multi-digit division problems.
• ➗ The remainder in a division problem can help determine the accuracy of the quotient.
• 😥 Moving the decimal point in the quotient corresponds to moving it in the original division problem.
• ✖️ The value of a fraction remains unchanged if the numerator and denominator are multiplied by the same quantity.
• 🗂️ Dividing by a two-digit number requires estimation and trial and error.

Questions & Answers

Q: How can we simplify the division problem 30.24 divided by 0.42?

The problem can be simplified by rewriting it as a fraction, 30.42 divided by 0.42. By multiplying both the numerator and denominator by 100, we can eliminate the decimal point and make the division easier to solve.

Q: What is the value of 30.42 divided by 0.42 after multiplying both the numerator and denominator by 100?

After multiplying the numerator and denominator by 100, the division problem becomes 3,042 divided by 42. We can then move the decimal two places to the right, resulting in 72.

Q: How do we divide 3,024 by 42?

To solve 3,024 divided by 42, we divide digit by digit. Starting with the leftmost digit, we find that 42 goes into 30 zero times. Moving to the next digit, 42 goes into 302 approximately 7 times. Subtracting the product of 7 and 42 from 302 gives us a remainder of 8. We then bring down the next digit and find that 42 goes into 84 two times, resulting in a final answer of 72.

Q: What is the key step in solving the division problem 30.24 divided by 0.42?

The key step is rewriting the division problem as a fraction and then multiplying both the numerator and denominator by the same quantity. This eliminates the decimal point and simplifies the division, making it easier to solve.

Summary & Key Takeaways

• The video teaches how to solve the division problem 30.24 divided by 0.42.

• By rewriting the division as a fraction and multiplying both the numerator and denominator by the same quantity, the problem becomes easier to solve.

• The final answer is 72.