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Grade 4 Math · World 6: Fraction Bakery · Level 55
Multiply by a Fraction for One
Make 3/4 = 9/12 by multiplying by 3/3.
Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.
What children learn in Level 55
- Multiplying a number by 1 doesn't change it: 7 times 1 is still 7. And 3 thirds is 1!
- So multiply 3 fourths by 3 over 3. Top: 3 times 3 is 9. Bottom: 4 times 3 is 12. You get 9 twelfths, the same size as 3 fourths.
- Be careful: adding doesn't work! Add 1 to the top and bottom of 1 half and you get 2 thirds, which is bigger.
- Multiply the top and the bottom by the same number. That's multiplying by 1, so the size stays the same.
Georgia's K-12 Mathematics Standards:
- 4.NR.4.1 — Using concrete materials, drawings, and number lines, demonstrate and explain the relationship between equivalent fractions, including fractions greater than one, and explain the identity property of multiplication as it relates to equivalent fractions. Generate equivalent fractions using these relationships.