Assignment 4
DUE 14 August 2025
,TMN3704
Assignment 4
DUE 14 August 2025
Question 1.5.1: What error did Moeli make?
Problem Statement:
Moeli attempted to simplify the addition of fractions:
His response:
Step 1: Understand the correct method for adding fractions
To add fractions, find a common denominator, convert each fraction to an equivalent
fraction with that denominator, add the numerators, and simplify if necessary. For + ,
the denominators are 3 and 6. The least common denominator (LCD) is 6.
Step 2: Perform the correct calculation
• Convert to a fraction with denominator 6: .
• Add to : + = = .
• Simplify : Divide numerator and denominator by 3, giving .
Step 3: Analyze Moeli’s response
Moeli’s steps:
• .
• This becomes + .
• Moeli then states = , which is incorrect.
1
, Step 4: Identify the error
• First error:
Moeli incorrectly manipulated the fractions.
For ,
Moeli wrote
, which is not equivalent to (since would be correct for a
denominator of 15). Similarly, for , Moeli wrote , which is correct but
inconsistent with the denominator used for .
• Second error:
Moeli added fractions with different denominators ( + ) without finding a
common denominator, leading to the incorrect claim that = .
• Third error:
The equality = is mathematically incorrect, as = and = , which are not
equal.
Final Answer: Moeli’s errors were: (1) incorrectly manipulating fractions to get
instead of for , (2) adding fractions with different denominators without finding a
common denominator, and (3) incorrectly stating = .
2