Add Fractions Notes & Questions | Class 5 Mathematics | Drishti OS

Add Fractions

To add like fractions by adding numerators and keeping the denominator.
To add unlike fractions by converting to a common denominator (LCD) first.
To simplify answers to lowest terms and express improper results as mixed numbers.
To solve NCERT Math-Magic 5, Chapter 4 style sharing problems (food, land, time).

Verbal: When denominators match, you are counting the same-sized pieces — just add how many pieces.

Symbolic: a/c + b/c = (a + b)/c

Verbal: Convert to equivalent like fractions using LCD, then add numerators.

Symbolic: 1/2 + 1/3 → 3/6 + 2/6 = 5/6

NCERT link: Math-Magic 5, Ch 4 — "Meena ate 1/4 of a cake and Raj ate 1/2. How much together?"

Real-life: Ravi walked 2/5 km to school and 1/5 km to the library — total 3/5 km.

Step	Action
1	Find LCD of denominators
2	Convert each fraction
3	Add numerators; keep denominator
4	Simplify if possible

Find 2/3 + 1/6

Step 1 — LCD of 3 and 6 = 6
Step 2 — 2/3 = 4/6; 1/6 stays
Step 3 — 4/6 + 1/6 = 5/6
Answer: 5/6

Meena ate 1/4 of a cake and Raj ate 1/2. Fraction eaten together?

Step 1 — LCD of 4 and 2 = 4
Step 2 — 1/2 = 2/4
Step 3 — 1/4 + 2/4 = 3/4
Answer: 3/4 of the cake

Mistake	Why it happens	Fix
1/2 + 1/3 = 2/5	Adding numerators and denominators	LCD → 3/6 + 2/6 = 5/6
Leaving 6/8 unsimplified	Stopping after addition	Always check HCF → 3/4
Wrong LCD (e.g. 24 instead of 12)	Using product not LCM	List multiples; pick smallest common
Forgetting to convert both fractions	Converting only one side	Every term must share the LCD

Revision tip: Before adding, ask: "Are they like?" If no, find LCD first. Write this as a three-step checklist on a sticky note.

Open the Practice tab for graded questions on Add Fractions.