Lesson 2 of 19
Renaming until the pieces match
Show on a big screenCut one strip into quarters. Cut another into sixths. A quarter piece and a sixth piece do not match.
Step 1 of 4
- Strip A in quarters, strip B in sixths.
- Shade 1/4 on A and 1/6 on B.
- Count up both lists: 4, 8, 12 and 6, 12.
- Both reach 12: 1/4 = 3/12, 1/6 = 2/12.
Find a shared cut
Fractions with the same bottom number are like fractions. You can add them at once. Fractions with different bottom numbers are unlike fractions. A bottom number both can be renamed onto is a common denominator.
| Word | Meaning | Example |
|---|---|---|
| Like fractions | Same bottom number | 3/8 and 2/8 |
| Unlike fractions | Different bottom numbers | 1/4 and 1/6 |
| Common denominator | A bottom number both reach | 12 |
Count up in steps of 4: 4, 8, 12. Count up in steps of 6: 6, 12. Both lists reach 12. 12 is 3 steps of 4, so 1/4 is 3/12. 12 is 2 steps of 6, so 1/6 is 2/12. Top and bottom are multiplied by the same number.
Tap a bottom number in the lab. Both strips are cut again to match it.
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Try the lab to finish this lesson.