National curriculum content

• 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.

Lesson objectives

1. Read and plot coordinates
2. Problem solving with coordinates
3. Translation
4. Translation with coordinates
5. Lines of symmetry
6. Reflection in horizontal and vertical lines

What we want children to know

• To use co-ordinates to describe position in the first quadrant
• To read, write and use pairs of co-ordinates
• To accurately plot co-ordinates on the grid lines
• To translate a shape on a grid focusing on one vertex at a time and the fact that the shape itself does not change size nor orientation when translated
• To know that if a whole shape is symmetrical the pattern inside the shape must also be symmetrical
• To reflect objects using lines that are parallel to the axes

What skills we want children to develop

Use knowledge to solve reasoning and problem solving questions such as:

These three co-ordinates have all been translated in the same way.

 ( _ , _ ) to (3, 1)

 ( _, 5 ) to (4, 3)

 (4, _ ) to (6, 1)

Can you work out the missing coordinates?

Describe the translation.

A square is translated 3 squares down and one square to the right.

Three of the coordinates of the translated square are:

(3, 6)      (8, 11)     (8, 6)

What are the co-ordinates of the original square?

Fred says that when you reflect a shape its dimensions change.

Do you agree? Explain your reasoning.

Mathematical Talk

• Which is the 𝑥-axis?

         Which is the 𝑦-axis?

         In which order do we read the axes?

         Does it matter in which order we read the axes?

         How do we know where to mark on the point?

         What are the coordinates for ______?

         Where would ( __ , __ ) be?

• Look what happens when I translate this shape. What has happened to the shape? Have the dimensions of the shape changed? Does it still face the same way?
• If I reflect this point/shape in a vertical/horizontal mirror line, what will happen to the 𝑥-coordinate/𝑦-coordinate?
• If we look at this point, where will its new position be on the image, when it is reflected? What’s different about the co-ordinates of the object compared to the coordinates of the image?
• Do you always need to use a mirror? How else could you work out the coordinates of each vertex?
• When I reflect something, what changes about the object? Is it exactly the same?