# Maths Year 4 Spring Shape

Each unit has everything you need to teach a set of related skills and concepts.

## Draw circles, study polygons, e.g. triangles(suggested as 3 days)

### Planning and Activities

Day 1 Teaching
Introduce the terminology for circles: radius, diameter, and circumference. Show children a compass and model how to use it to draw a circle. Discuss drawing circles with specified radii. Observe that the diameter is double the radius.
Group Activities
-- Use compasses to draw circles with measured radii.

Day 2 Teaching
Show a large 50p coin and agree (having noted slightly curved sides and rounded corners) that it is a heptagon. Children draw irregular heptagons. Identify types of angle within it. Explain that all polygons have straight sides and are closed. Discuss what makes a good description of a polygon.

Group Activities
-- Identify the properties of polygons and use this to sort them.
-- Draw 2-D shapes based on given properties.

Day 3 Teaching
Show children five different triangles and discuss their similarities and differences. Look at the number of sides and angles, lines of symmetry, length of sides, sizes of angles. Name the triangles as: equilateral, isosceles, right angled, scalene. Note that a right angled triangle can also be isosceles. Sort triangles according to different properties, e.g. has a right angle or not.
Group Activities
Use the in-depth problem-solving investigation ‘Egyptian Rope’ from NRICH as today’s group activity.
Or, use this activity:
-- Identify right angles and other properties in triangles; classify them.

### You Will Need

• A circle: pre-drawn and annotated (circumference, radius, diameter)
• Compasses, large pieces of paper, glue, sticky notes and rulers
• cm cards (see resources)
• Range of sharp coloured pencils and scissors
• Picture of 50p coin (or large mock 50p coin)
• ‘Polygons to sort’ sheet (see resources)
• Paper equilateral triangle
• Additional activity sheets (see resources)

### Mental/Oral Maths Starters

Day 1
2-D shapes (pre-requisite skills)

Suggested for Day 2
Telling the time (simmering skills)

Suggested for Day 3
Complete symmetrical drawings (simmering skills)

### Worksheets

Day 1
Draw circles of given radii using compasses.

Day 2
Guess the shape game.

Day 3
Name triangles and identify right angles and other properties.

### Mastery: Reasoning and Problem-Solving

• Always true, sometimes true or false?
The circumference of a circle is the distance across the centre from one side to the other.
The radius of a circle is half the diameter.
A circle is a special type of polygon.
A pentagon is a regular five-sided polygon.
A polygon has eight sides.
• Draw triangles to match each description.
With a right angle and the shortest side is 3cm.
Two sides and two angles are equal.
No equal angles; one side twice as long as one other side.