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11+ Non-Verbal Reasoning · Year 5–6 · Free lesson

Counting and Overlaps

How many triangles? More than you first see — combinations count. Labelling regions and sweeping sizes smallest-to-largest turns NVR counting from squinting into arithmetic.

N11Counting and Overlaps
Count regions, not impressions.
Overlap questions count regions and intersections — systematically, smallest to largest.
How many regions?
123
Two overlapping circles → 3 enclosed regions (left-only, overlap, right-only).
Label as you count — numbers on the figure beat eyes alone.
1

Learn the 3-Step Method

1Regions: label each enclosed area.

Write tiny numbers in every separate area as you count — no area counted twice or missed.

label 1, 2, 3…

2Intersections: count crossing points.

Two circles cross at 2 points; add a line through both and each crossing adds more — mark each dot.

mark crossings

3Composite shapes: smallest to largest.

Counting triangles in a figure? Count the small ones, then those made of 2, then of 4 — sizes in order.

small → large
💡 Key Idea‘How many triangles?’ questions hide the big ones: combinations count too — a triangle split once contains 3 (two small + the whole).
2

Worked Example

A large triangle is split by one line from apex to base. How many triangles in total?

Small ones
left small + right small = 2
Combinations
the whole outline = 1 more
✓ Total
2 + 1 = 3
3

Watch Out! Common Mistakes

Counting only the obvious pieces.

The whole counts! Small shapes combine into bigger ones — the outline triangle is the most-missed answer in counting questions.

Double-counting the overlap.

Label it once! The lens where circles overlap is ONE region. Writing numbers in regions prevents recounting.

Eye-counting complex figures.

Pencil beats eyes! Past four regions, unlabelled counting fails. Tiny numbers or ticks make it mechanical.

Cheat Sheet

COUNTING AND OVERLAPS
  1. Write a number in every enclosed region.
  2. Mark every crossing point as you count.
  3. Composite counts: smallest shapes, then combinations by size.
  4. The whole outline is usually a shape too.
Examples: 2 overlapping circles → 3 regions · split triangle → 3 triangles.
📄 Free printable: Download the Counting and Overlaps cheat sheet (PDF) — keep it by your child's desk.

Quick summary

Frequently asked questions

How many regions do two overlapping circles make?

Three enclosed regions — left-only, the overlapping lens, and right-only — plus the outside, which questions usually exclude.

Why do children undercount triangles?

They stop at the visible small pieces and miss combinations — a triangle split by one line contains three triangles, not two.

What's the reliable counting method?

Pencil labels: number each region, tick each shape size class in order. Mechanical counting doesn't tire or skip.

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