Dividing a whole number by a decimal | Decimals | Pre-Algebra | Khan Academy

TL;DR

Dividing 518 by 0.7 is equivalent to dividing 5,180 by 7.

Transcript

Let's divide 518 by-- so we're going to divide it by 0.7. So we're dividing this whole number by a decimal. So we could also write this as 518 divided-- let me write a little bit bigger than that, since we have to do some work with it. 518 divided by-- I'll do the division sign in white-- divided by 0.7. So the first thing we do, since we have this... Read More

Key Insights

• #️⃣ Dividing a whole number by a decimal can be simplified by converting the decimal into a whole number through multiplication.
• 🧑‍🏭 Multiplying both numbers in the division problem by the same factor preserves the result.
• ➗ Converting a decimal division problem into a fraction can assist in simplifying the calculation.

Questions & Answers

Q: How do you convert the decimal 0.7 into a whole number in the division problem?

To convert 0.7 into a whole number, you multiply it by 10, shifting the decimal point one place to the right. This results in the decimal becoming a 7.

Q: Why is it necessary to multiply both numbers by 10 in the division problem?

Multiplying both numbers by 10 preserves the value of the division, ensuring that the result remains the same. It allows us to convert the decimal 0.7 into a whole number, while also adjusting the dividend (518) by moving its decimal point one place to the right.

Q: How can the division problem be expressed as a fraction?

The division problem 518 divided by 0.7 can be written as 518/0.7. To simplify the fraction, you multiply both the numerator and denominator by 10, resulting in 5,180/7.

Q: How is the long division method used to solve the division problem?

The long division method is used to find how many times 7 can be divided into each digit of the dividend. By performing the calculations step by step, we find that 7 goes into 51 seven times, 7 goes into 28 four times, and so on, until there is no remainder.

Summary & Key Takeaways

• The division problem involves dividing 518 by 0.7, which is a decimal.

• To simplify the division, both numbers are multiplied by 10 so that the decimal becomes a whole number.

• The result of dividing 518 by 0.7 is equivalent to dividing 5,180 by 7.