I am going to slide this triangle across the grid: three squares to the right, then two squares up. Same triangle, new spot on the map.

Watch four slides on the grid. Each time, a shape moves without turning or flipping — every corner travels the same distance in the same direction. The new shape we get after a slide is called its image. Read the corner numbers off the labelled grid and keep your eye on where each corner lands.

Before each slide, say what you think the new co-ordinates of one corner will be, then we check them on the grid together.

Each time, read the new co-ordinates of every corner off the labelled grid. Then we check them together.

Now we work through these together on the board, matching the shape to the dashed target outline each time. We begin with a straight slide to the right, then a slide down, and then a diagonal slide that moves the shape in two directions at once. The last one is different: before anyone moves the shape, you have to describe in words the slide that gets there.