Ray's New Practical Arithmetic · Arts. 102–105 · Unit 10: Fractions
54. Reduction of fractions, Cases I–III
Goal: Your child changes whole numbers and mixed numbers to improper fractions and improper fractions back to whole or mixed numbers.
You'll need
- The book
- A slate, small whiteboard or scrap paper
- A notebook and pencil
What's in the book
Reduction of fractions, Case I (an integer to an improper fraction), Case II (a mixed number to an improper fraction), and Case III (an improper fraction to a whole or mixed number), each with a rule and problems.
The lesson, step by step
Warm-up
Mental: halves in 3 apples? (6.) Thirds in 2 apples? (6.) Fourths in 3 dollars? (12.)
The idea
Read:
Reduction of Fractions is changing their form without altering their value.
Case I:
To reduce an integer to an improper fraction, having a given denominator.
Multiply the integer by the given denominator; under the product write the denominator.
Case II
Work the book's example: In 3½ apples, how many halves? 3 apples are 6 halves, and 1 half more makes 7 halves.
6 halves and 1 half are 7 halves.
SayMultiply the whole number by the denominator and add the numerator.
Case III
Read:
To reduce an improper fraction to an integer or mixed number.
Divide the numerator by the denominator; the quotient will be the integer or the mixed number.
Example: 9/4 of a dollar: 9 ÷ 4 = 2, with 1 fourth over: 2¼ dollars.
Guided practice
Together, from the Case I list:
Reduce 4 to sevenths.
Then two from Case II and two from Case III.
Independent practice
Your child does about eight problems from each case.
Check and wrap-up
Answers are printed beside the problems. Mental: 2½ = how many halves? 11/3 = what mixed number?