Translation or reflection?: what children learn
Year 5 pupils identify, describe and represent the position of a shape following a reflection or translation.
In this game children sort descriptions of movements into translation, reflection and neither. A translation slides a shape. A reflection flips it over a mirror line. Turning or resizing a shape is neither.
This topic covers the Year 5 statutory requirement in the National Curriculum in England (Geometry – position and direction): pupils should be taught to “identify, describe and represent the position of a shape following a reflection or translation, using the appropriate language, and know that the shape has not changed”. Year 5 pupils are usually aged 9–10.
There is no direct equivalent in the US Common Core State Standards. Translations and reflections are Grade 8 in Common Core (8.G.A.1).
How to play
Sort the cards into the right groups. Tap a card, then its group. You can also drag a card, or press the number on its group. Each game has 3 rounds with no timer. Every card is checked as soon as you place it: a card in the wrong group comes back with a hint, and you get a point for each card you place right first time. For a quicker go, choose Quick quiz: 10 multiple-choice questions in 150 seconds (choose Relaxed for more time).
Step by step
- Translation: a slide. The shape moves left, right, up or down without turning or flipping.
- Reflection: a flip. The shape flips over a mirror line and faces the other way.
- Neither. Turning, stretching or resizing a shape is a different kind of change.
- Check the shape. After a translation or reflection, the shape is the same size and shape.
Worked examples
Example 1: A triangle slides 3 squares to the right without turning
Working: It slides.
Answer: translation
Example 2: A shape flips over a mirror line
Working: It flips.
Answer: reflection
Example 3: A triangle is made twice as big
Working: It changes size.
Answer: neither
Common mistakes and how to fix them
- Thinking any movement is a translation. Ask: did it turn or flip? If it did, it is not a translation.
- Calling a turn a reflection. A reflection needs a mirror line. A turn goes round a point.
- Thinking a reflection changes the shape. A reflected shape is the same shape, facing the other way.
Activities to try at home
- Slide, flip and turn a cut-out shape on the table and name each movement.
- Look for reflections in windows and puddles.
- Find patterns in wallpaper or tiles made by translating a shape.
Ideas for the classroom
- Pupils describe the movement between two positions of a shape on a grid.
- Act out translations and reflections with pupils as the shapes.
- Make a pattern by translating one shape across squared paper.
Free printable game and worksheet
The free printable starts with a game sheet, such as a colour-by-answer picture, an answer maze or a secret-code joke, followed by a worksheet. Both use the same checked questions as the online game, and the answers are on the last page. Print it, or save it as a PDF from your browser’s print menu.
Open the free printable game and worksheet
Frequently asked questions
What about rotations?
Rotations are usually taught at secondary school, which is why they count as 'neither' here.
Why does this matter?
Describing movements precisely is the start of geometry with transformations.
Can it be played with a keyboard?
Yes. Tab to a card, press Enter to pick it up, then choose the group it belongs in.