3. Division of a fraction by an integer.

Deepen your knowledge with an interactive video lesson on this topic in our app. Quizzes and pauses will help you better absorb the material!

In this lesson, I will discuss dividing a fraction by a whole number. Imagine you're on a hike with friends. Yesterday for dinner, each of you ate one-sixth of a pizza slice, and today for breakfast, you have only two-sixths of the pizza left. Now, you need to divide the remaining evenly among four people. For convenience, we shorten two-sixths to one-third and divide by four. Note that we multiply the denominator by four (because the denominator indicates how many parts the whole is divided into), and the result is one-twelfth. So, each of you will eat one-twelfth of yesterday's pizza for breakfast. Another example: let's divide a watermelon. Suppose you have a quarter of a watermelon, and you need to split it into four equal parts among family members. So, one-quarter divided by four is... try to recall the trick we did with the denominator earlier, then keep watching. Hopefully, we match: we multiply the denominator by four, and the result is one-sixteenth for each family member. What else haven't we divided? Chocolate! Now let's split a chocolate bar: I have one-quarter of a twenty-four-piece chocolate bar – that's six twenty-fourths, and I will divide it by three – don't ask why, I just want to and can! Let's skip the visuals and get right to the calculations. Six twenty-fourths divided by three, as always, let's simplify first, what did you get? I got one-quarter, did I not mention that earlier? Now, we continue the operation with the denominator, remember the trick? Right, we multiply the denominator by three, and the result is one-twelfth. As always, once you understand, it becomes simple. Remember: when dividing a fraction by a whole number, you multiply the denominator. The fraction's denominator shows how many parts the whole is divided into, so the larger the denominator, the more parts the whole is divided into. Although multiplying during division might seem illogical at first, by multiplying the denominator, we make the fraction smaller by the number of times we wish to divide. It's not at all complicated; you just need to practice.

Mastering Fraction Division by Whole Numbers for Students

Dividing Fractions by an Integer Made Easy

Understanding how to divide a fraction by a whole number can sometimes seem challenging, but with a little practice, it becomes quite straightforward. While the video lesson demonstrates the basics using pizza, watermelon, and chocolate examples, let's delve a bit deeper with additional examples and tips to master this concept.

Why Multiply the Denominator?

When you divide a fraction by an integer, you essentially spread the fraction into more, smaller parts. This is why we multiply the denominator by the integer. This operation transforms the original fraction into a smaller fraction, representing a smaller portion of the whole. It's like cutting a cake into more pieces so more people can have a share!

Example Simplified

Imagine you have half a cake, and you want to share it with three friends equally. In mathematical terms, you're dividing 1/2 by 3. Instead of thinking of this as a division problem, think of it as multiplying the denominator (2) by 3. So, 1/2 divided by 3 is the same as 1/(2*3), which simplifies to 1/6. Thus, each person gets one-sixth of the cake.

Practical Application

Consider a scenario where you have three-fifths of a gallon of paint and need to distribute it equally among five painters. By applying our rule, divide three-fifths (3/5) by 5. Multiply the denominator (5) by 5, resulting in 3/25. This means each painter gets three-twenty-fifths of a gallon to paint with.

Quick Tips for Mastery

  • Always simplify - Before dividing, simplify the fraction if possible. This makes the math easier.
  • Practice makes perfect - Work on various examples to become comfortable with different scenarios.
  • Remember the rule - When in doubt, recall that dividing by an integer means multiplying the denominator by that integer.

With these insights and examples, you're well on your way to mastering the division of a fraction by an integer. It's all about seeing each piece and person getting their fair share!