1) Fractions: Add & Subtract
5.NF.A.1
5.NF.A.1
First, make sure you can add and subtract fractions that share the same denominator.
Let's cover the basics: 4 < The top # in a fraction is the numerator. 5 < The bottom # in a fraction is the denominator. Fractions with COMMON denominators have the same (like) denominator. Example: 1 5 25 4,842 all have 8 as a 8 8 8 8 denominator When fractions have common denominators, add or subtract the numerators. Example: 1 + 5 = 6 6 - 4 = 2 8 8 8 8 8 8 Starting easy: Fractions with the same denominator Video: Finding Common Denominators Video: Adding Fractions with Like Denominators Video: Common Denominators: 1/4 & 5/6 Practice with Common Denominators Fractions with UNLIKE denominators have different (unlike) denominators. Example: 1 5 25 4,842 2 6 60 358 How do we add fractions with unlike denominators? |
In case you'd like to read the CA State Standards:
Big Idea: I can add and subtract fractions with unlike denominators. Use equivalent fractions as a strategy to add and subtract fractions. 1. 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.) Now let's add and subtract fractions that have different (unlike) denominators... Video: Add Fractions with Unlike Denominators Practice Adding Fractions (unlike denominators) Video: Subtract Fractions with Unlike Denominators Practice Subtracting Fractions (unlike denominators) OK! Now you're ready for Mixed Numbers... Start easy... you won't have to regroup with these... Video: Subtract Mixed Numbers (unlike denom.) Video: Add Mixed Numbers (unlike denom.) Practice: Add & Subtract Mixed #s (unlike denom) Now we'll take on adding and subtracting mixed numbers where we need to regroup.... Video: Add mixed #s (need to regroup) Video: Subtract mixed #s (need to regroup) Video: Subtract 7 6/9 - 3 2/5 Practice: Add & Subtract Mixed #s (need to regroup) |