Here is a clean, classroom-ready 15-minute lesson designed to pair directly with the Math-Aids Dividing Fractions worksheet. The worksheet focuses on the invert-and-multiply method and offers three difficulty levels, with 10 or 15 problems per worksheet.

Grade Level: 5–7
Time: 15 minutes
Topic: Dividing Fractions Using Keep, Change, Flip
Students will divide fractions by keeping the first fraction, changing division to multiplication, flipping the second fraction, and simplifying the answer.
Pencil
Whiteboard or projector
Write this problem on the board:
2/4 ÷ 2/10 = ?
Explain that the top number is the numerator and the bottom number is the denominator.
Teach students to follow three steps:
Keep the first fraction.
Change the division sign to multiplication.
Flip the second fraction.
Show the problem again:
2/4 ÷ 2/10
Keep 2/4, change ÷ to ×, and flip 2/10 to 10/2.
Now the problem becomes:
2/4 × 10/2
Work through the first worksheet problem together.
2/4 ÷ 2/10
Step 1: Keep, change, flip.
2/4 × 10/2
Step 2: Multiply the numerators.
2 × 10 = 20
Step 3: Multiply the denominators.
4 × 2 = 8
Step 4: Write the answer.
20/8
Step 5: Simplify.
20/8 = 5/2 = 2 1/2
2/3 ÷ 1/2
Step 1: Keep, change, flip.
2/3 × 2/1
Step 2: Multiply across.
2 × 2 = 4
3 × 1 = 3
Step 3: Write and simplify the answer.
4/3 = 1 1/3
Remind students: Only flip the second fraction!
Complete these actual worksheet problems together.
4/10 ÷ 1/2
Keep, change, flip:
4/10 × 2/1
Multiply:
4 × 2 = 8
10 × 1 = 10
Simplify:
8/10 = 4/5
2/3 ÷ 2/4
Keep, change, flip:
2/3 × 4/2
Multiply:
2 × 4 = 8
3 × 2 = 6
Simplify:
8/6 = 4/3 = 1 1/3
Ask students to explain which fraction they flipped and why.
Have students complete as many of the remaining worksheet problems as possible.
Use this simple reminder on the board:
KEEP → CHANGE → FLIP → MULTIPLY → SIMPLIFY
The remaining problems are:
Problem 4: 9/10 ÷ 1/2
Problem 6: 1/2 ÷ 2/4
Problem 7: 2/3 ÷ 1/5
Problem 8: 3/5 ÷ 1/2
Problem 9: 1/2 ÷ 8/10
Problem 10: 1/2 ÷ 2/3
Encourage students to show each step rather than write only the final answer.
Use worksheet Problem 8:
3/5 ÷ 1/2
Step 1: Keep, change, flip.
3/5 × 2/1
Step 2: Multiply.
3 × 2 = 6
5 × 1 = 5
Step 3: Simplify or convert to a mixed number.
6/5 = 1 1/5
Ask students to explain the three steps of keep, change, flip.
Students needing support:
Complete Problems 1–3 with teacher assistance.
Keep the five-step reminder visible.
Allow students to use a multiplication chart if needed.
Students working at grade level:
Complete the remaining worksheet problems independently.
Require students to show the multiplication and simplification steps.
Students needing a challenge:
Complete all 10 problems.
Convert improper fractions to mixed numbers.
Check answers by multiplying the quotient by the divisor.
Flipping the first fraction instead of the second.
Forgetting to change division to multiplication.
Multiplying only the numerators or only the denominators.
Forgetting to simplify the answer.
Students demonstrate understanding when they can:
Apply keep, change, flip correctly.
Multiply the fractions accurately.
Simplify their answers.
Convert improper fractions to mixed numbers when appropriate.
“I can divide fractions by keeping the first fraction, changing division to multiplication, flipping the second fraction, and simplifying my answer.”
Teacher tip: For a 15-minute lesson, start with the worksheet’s easiest setting. Focus first on mastering the procedure, then introduce more complex fractions as students become confident.
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Posted 10/13/26
Education World®