Look at this paper butterfly. If we folded it right down the middle, both wings would land exactly on top of each other.

Where else could you fold a shape so the two halves match perfectly? Have a think before any hands go up.

Watch the shapes fold on the board. When a shape folds so both halves land exactly on top of each other, that fold is a line of symmetry, also called a mirror line. Watch how many ways each shape folds to match.

So some shapes fold to match in lots of ways, and some only fold to match once.

Each shape is drawn for you on the grid. For each one, decide where it folds so that one half lands exactly on the other, choose those folds, and check. We work through a letter T, a rectangle, a square and an L-shape — and one of them has no fold at all.

Today we work through these shapes together: a heart, then a rectangle. For each one, find the lines of symmetry, the folds where both halves match exactly.

What we learned today

• A line of symmetry, also called a mirror line, folds a shape into two halves that land exactly on top of each other.
• We test a fold by checking the halves cover each other, not just by drawing any straight line.
• Some shapes have one line of symmetry, some have several, and a circle has too many to count.