6.2.1 Estimate Products of Fractions

We will be looking for compatible numbers that work between the denominator and the whole number:

• • For example, Let's say that  I'm looking for 1/3 of 10. Since the denominator, which is 3, does not go into 10 nicely, we will change the 10 into a 9 (since 3 DOES go into 9)

  • So now, I'm looking for 1/3 of 9, which is essentially splitting 9 into 3 equal parts. Now the numerator of our fraction, which is 1, tells use that we need one of those parts. Since each of our parts is split into 3, our answer is three.

• Models of a few examples of this are listed below

We can also estimate when it comes to multiplying fractions by fractions. 

• • For example, we may have the problem 5/8 x 9/10.

    • Well, 5/8 is very close to 1/2 and 9/10 is close to 1, so what we really have is 1/2 x 1.

    • 1/2 of 1 is equal to 1/2 so that is our approximate answer.

  • A model of another example is listed below.