You are adding fractions. To add fractions, they all must have the same denominator.
We are adding 2/3 + 1 1/2 + 1/4.
First, let's turn that mixed number (1 1/2) to an improper fraction.
Multiply the whole number by the denominator: 1*2=2
Add that to the numerator: 2+1=3
Write that over original denominator: 3/2
2/3 + 3/2 + 1/4
Okay, now we need common denominators.
What is the LCM (lowest common multiple) of 3, 2, and 4? The lowest common multiple is the lowest number that they all equal when multiplied by something. The LCM is 12.
3*4=12
2*6=12
4*3=12
When multiplying the denominators by the LCM, you must also do the same to the numerators!
Make sure to multiply the numerators by the same number you multiplied by the fractions!
So now we have:
8/12 + 18/12 + 3/12
So now that our denominators are all the same, all you have to do is add the numerators and keep the denominators the same!
8+18+3=29/12
29/12 is our answer. We could also changed this to a mixed number and reduce.
12 goes into 29 evenly 2 times, with a remainder of 5. Keep the denominator. Mixed number form is 2 5/12. This can't be reduced (5 is prime) so Ms. Martinville needs 2 5/12 altogether!