Complex LCM: Error Analysis & Misconceptions
Mathematics
Grade 7
13 questions
~26 mins
1 views0 downloads
About This Worksheet
This worksheet focuses on understanding and applying the concept of Complex LCM when adding fractions with unlike denominators. It includes error analysis and misconception correction activities to deepen understanding.
Worksheet Preview
Full preview • 13 questions
Complex LCM: Error Analysis & Misconceptions
Subject: MathematicsGrade: Grade 7
Name:
Date:
TeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizzTeachWhizz
Untitled Worksheet
Grade Grade 7
A
Fluency & Practice
Solve the following questions by calculating the LCM and adding the fractions. Show your working in the grid spaces provided.
1.
Add: 3/8 + 5/12. Find the LCM of 8 and 12 and write the sum.
[2 marks]2.
Add: 7/9 + 2/6. Show your step-by-step calculation.
[2 marks]3.
Calculate: 11/15 + 4/20. Use the LCM method to add.
[2 marks]4.
Simplify the sum of 2/14 + 3/21. Identify the mistake if the answer is incorrect.
[2 marks]B
Problem Solving & Reasoning
Solve these multi-step problems involving Complex LCM. Explain your reasoning.
1.
A recipe requires 2/5 cup of sugar and 1/3 cup of honey. You want to prepare a larger batch using the least common multiple of the denominators to find equivalent fractions. How much total ingredient is needed if you scale up to the LCM?
[3 marks]2.
Explain why finding the LCM of denominators is essential when adding fractions. Illustrate with an example.
[3 marks]3.
A student adds 3/10 + 5/15 and writes the answer as 1/2. Describe the mistake and correct it.
[3 marks]C
Real-world Applications
Apply your knowledge of Complex LCM to solve real-world problems.
1.
Two timers ring at different intervals: one every 6 minutes and another every 8 minutes. When will they ring together again after starting at the same time? Use LCM to solve.
[2 marks]2.
A cyclist rides every 12 miles and another every 15 miles. If they start riding at the same time, after how many miles will they both arrive at the starting point simultaneously? Use LCM.
[2 marks]D
Challenge & Extension
Attempt these more challenging problems involving complex LCM concepts.
1.
Prove that the LCM of any two numbers is always divisible by their greatest common divisor (GCD). Provide an example with your explanation.
[4 marks]2.
Find the LCM of three numbers: 4, 6, and 8. Show your step-by-step process.
[3 marks]E
Mixed Review & Error Analysis
Identify the errors in the following solutions and correct them.
1.
A student adds 2/5 + 3/10 and writes the answer as 1/2. What was the mistake? Correct the answer.
[3 marks]2.
A student finds the LCM of 9 and 12 as 36 and adds 4/9 + 5/12. Identify and correct the mistake.
[3 marks]Quick Actions
What is Remix?
Create a new worksheet based on this one. Change the grade level, topic, number of questions, or difficulty - then generate a fresh version.
- • Change grade level (Grade 6 → Grade 7)
- • Swap topics (Harry Potter → Macbeth)
- • Add more questions (10 → 15)
- • Adjust difficulty
Details
- Created
- 1/1/2026
- Updated
- 1/1/2026
- Type
- worksheet