Primary 6 Maths: Area & Circumference of Circle

Updated Sept 2026

Radius, diameter, circumference and area of circles, plus semicircles, quarter circles and composite figures — the P6 circle topic that PSLE loves to combine with other shapes.

Most schools typically cover this topic in Term 2, around weeks 5–7 — though every school sets its own sequence.

Circles arrive at Primary 6 with a short, sharp scope: the parts of a circle, circumference, area, and the same two formulas applied to semicircles, quarter circles and shapes built by combining a circle with a rectangle, triangle or square. The harder exam questions rarely stop at "find the area of this circle": they ask for a shaded region made of two or three pieces, at least one of them curved.

The whole topic runs on two formulas: circumference = 2 × π × r (or π × d) and area = π × r². Each question tells the child which value of π to use: "Take π = 3.14", "Take π = 22/7", or, on the calculator paper, the calculator's π key. A radius that's a multiple of 7 usually comes with 22/7, because the 7s cancel.

The mistakes to watch for

• Using a different π from the one the question gives. The instruction ("Take π = 3.14" or "Take π = 22/7") is part of the question; using the other value gives an answer that won't match the marking scheme, even though the method is right. Read it before starting.
• Halving area or circumference incorrectly for composite pieces. A semicircle's area is half the full circle's area, but a semicircle's perimeter is half the circumference plus the diameter — the straight edge doesn't disappear.
• Confusing radius and diameter mid-question. Circumference and area formulas both use radius; a question that gives the diameter needs a halving step first, easy to skip under time pressure.
• Forgetting a piece in a composite figure. Shaded-region questions often need one addition and one subtraction (or two of each) — sketch which whole shapes are being added and which are being removed before calculating anything.

Parts of a circle, and a corner shaded region

Easy: radius, diameter, circumference and area

Exam: semicircles, quarter circles and finding an unknown radius

PSLE challenge: composite figures with two or more circle pieces

How to practise this topic

Circle questions are formula-simple and setup-hard: the arithmetic is short once the right pieces are identified, so the practice that pays off is sketching what's being added and what's being removed before touching a calculator, and noting which value of π the question gives. Because this topic almost always shows up mixed with rectangles, squares and triangles inside a single multi-step question, it's also good practice for PSLE problem-solving more broadly.

What this topic covers

In the MOE Primary Mathematics syllabus, Primary 6 Area & Circumference of Circle includes the concepts below. (P6-M-08 is Test Paper's own topic code, not an MOE reference.)

• Parts of a circle (radius, diameter, circumference)
• Circumference of circle
• Area of circle
• Semicircle and quarter circle
• Area/perimeter of composite figures involving circles

Before this topic

These topics feed into Area & Circumference of Circle — if this one wobbles, check them first: Primary 5 Area & Perimeter · Primary 5 Decimals.

Where to go next

• Other Primary 6 topics: Primary 6 PSLE Problem-Solving · Primary 6 Fractions · Primary 6 Percentage
• All Primary 6 Maths topics, or every P4–P6 topic
• Not sure this is the weak topic? How to find which Maths topics your child is weak in
• Heading for PSLE? How PSLE AL bands and the PSLE Score work