Today I will show you how to add 2 fractions with a whole number. It’s easy and like any other addition of fractions that we have seen in previous videos. There are several methods to add a whole number and 2 fractions, here I will show 2 of them, choose your favorite!
Content:
1) Add 1/2 + 2/3 + 5
In this first example, we will used the LCM. So first, we need to convert the whole number (3) to a fraction, and the easiest way to convert a whole number to a fraction is by putting 1 as the denominator, so the whole number 3 becomes the fraction 3/1.
Now we need to add 3 fractions: 1/2 + 2/3 + 3/1. To find the sum, first we find the least common multiple (LCM) of the denominators (2, 3 and 1). The value of the LCM is 6.
Next we divide the LCM (6) by the first denominator (2), then we multiply the quotient (3) by the first numerator (1). We do the same with the 2 fractions remaining. And finally, we find the sum.
Done! The final answer is 25/6. If you want, you can convert this improper fraction to a mixed number, in that case the answer is 41/6.
2) Find the sum 2/3 + 3/4 + 3
In this example, we will use a faster method. First, we add 2/3 + 3/4 using the cross products method. The denominator of the resulting fraction is the product of the 2 denominators (3 × 4). Next, to find the numerator of the resulting fraction, we multiply the first numerator (2) by the second denominator (4) and then we add the product of the first denominator (3) by the second denominator (3).
In the following step, we add the fraction 17/12 to the whole number 3. To add a fraction to a whole number, first, we multiply the denominator (12) by the whole number (3). Lastly we add this result to the numerator (17).
The sum is 53/12. If you want, you can convert this improper fraction to a mixed number, in that case, the answer is 45/12.
Video
In the following video, you will find another example.
That concludes today’s lesson, however, you take a look at my other fractions lessons.