Dot grid paper, 1 cm, for A4

Dots are the right paper for drawing shapes on. A quadrilateral drawn corner to corner on a centimeter grid has sides a child can count and an area they can work out by cutting it into rectangles — and none of the pencil lines are competing with a printed grid for attention.

It is also the paper for arrays. Six dots by four dots is a picture of 6 × 4 that a child can circle in rows or in columns, which is commutativity drawn rather than asserted, and it is much harder to see when the dots are a quarter of an inch apart.

The rules are drawn as real strokes at real sizes — not a picture of lines, and not a background tint. That matters more than it sounds: browsers drop background graphics when printing unless the reader has gone looking for the setting, so ruled paper made the obvious way looks perfect on screen and comes out of the printer blank. Put a ruler on this one. It is the size it says it is.

This sheet is set for A4 — 210 × 297 mm. Paper size is not a preference here: sent to a printer loaded with something else, the browser shrinks the page to fit, and a ruling that has been shrunk is no longer the size it was chosen for. So there is a second copy of this sheet, ruled identically and measured for US Letter.