In order to compare fractions they need to have common denominators, or wholes. We used knowledge from earlier in the year when finding Least Common Denominators because we had to use the multiples of numbers to find the LCD.
Today we began using these skills to help us add and subtract fractions with unlike denominators.
CCSS 5NF.A.1 is: Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12. (In general, a/b + c/d = (ad + bc)/bd.)
We practiced the stages of working through fraction problems to make sure we had Least Common Denominators, changing them to equivalent fractions that can be added/subtracted, then simplifying (reducing) if necessary.
Here are some examples we worked through, noting that although neither had hard numbers, one has nine steps to solve, and the other only three steps.
Next steps will include using fractions that are mixed and improper.
