Add and subtract fractions with unlike denominators

Start lessonBegins with Adding subtracting unlike denominators · Slides

Teacher tools for this standard

Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework

Lesson Plan →Objectives, pacing and practice, built from this lesson's brief.
Guided Notes →One page your students fill in and keep.
Exit Ticket →Three items at the end of class. No student accounts.
Re-teach →After an exit ticket: who missed what, and what to do tomorrow.
Homework →Assign practice; it grades itself.

5.NF.A.1

**5.NF.A.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.)

5.NF.A.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.)

What you'll learn

Explain why fractions with unlike denominators cannot be added or subtracted directly - the pieces are different sizes, so counting them together does not produce a meaningful result
Find a common denominator for two fractions by listing multiples or by multiplying the two denominators
Convert each fraction to an equivalent fraction with the common denominator, applying the principle that multiplying both the numerator and denominator by the same nonzero number does not change the fraction's value
Add fractions with unlike denominators (including mixed numbers) and express the result in simplest form
Subtract fractions with unlike denominators (including mixed numbers) and express the result in simplest form

Slides

Step through the lesson, or watch it as a narrated video

Adding subtracting unlike denominators

✓ Start here

Watch as video

Practice

Try it on your own

Exercise

Practice problems, checked as you go

Was this lesson helpful?

Report a problem with this page