CCSS.MATH.3.OA.A.1 / TEKS 3.4.D.7✓ NSW Education Standards Authority (NESA) AlignedAcademic Year 2026–27
Adding & Subtracting Like Fractions
Add and subtract fractions with identical denominators by operating on numerators while keeping the unit size constant.
Why It Matters:Vital for constructing blueprints, calculating split times, and medication dosage planning.
Curated Video Instruction
● Verified Active EmbedSTEP-BY-STEP PROOF
Worked Example
Calculate 3/8 + 4/8:
1
Confirm common denominator
Denominator = 8
Both fractions are measured in eighths.
2
Add numerators
3 + 4 = 7
Sum the counted parts.
3
Write result over common denominator
7/8
Result is 7/8.
✓Verification Check
Verify by subtraction: 7/8 - 4/8.
7/8 - 4/8 = 3/8
•
3/8 = 3/8
⚠️ Common Pitfalls & Misconceptions
Adding denominators together
✗ Calculating 3/8 + 4/8 = 7/16✓ Denominators define the unit size; only numerators are added
3 eighths plus 4 eighths is 7 eighths, not sixteenths.
INTERACTIVE DRILLS
Guided Practice
Practice Question1 of 1
Step-by-step Feedback
What is 5/10 + 3/10?
MASTERY BENCHMARK
Official Assessment Quiz
Formal Assessment
Adding & Subtracting Like Fractions
Passing Criteria:70% or higher
Question 1 of 1
What is 7/12 - 2/12?
Education to Career Navigation
Where This Lesson Leads
Nurses, Athletic Trainers, and Mechanical Drafters operate with fractional units daily.