### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Define and explore lines of symmetry using online animations/examples.**Further Teaching with Y4**

Explore symmetrical patterns on a square grid.**Group Activities: T with Y4**Use the ‘Tremendous tiles’ in-depth problem-solving investigation below as today’s group activity.

Or, use these activities:

Y3 -- Complete symmetrical pictures, either pre-drawn or self-drawn.

Y4 -- Create patterns with horizontal or vertical lines of symmetry.

**Day 2 Teaching**Explore regular and irregular heptagons and their properties.

**Further Teaching with Y3**

Identify properties of polygons and use associated vocabulary.

**Group Activities: T with Y3**

Y3 -- Introduce the Venn diagram; use it for sorting 2-D shapes.

Y4 -- Sort polygons into a Carroll or Venn diagram.

**Day 3 Teaching**Describe and sort irregular polygons.

**Further Teaching with Y4**

Classify types of triangles, learning associated vocabulary.

**Group Activities: T with Y4**

Y3 -- Sort a wide range of 2-D shapes into a Venn diagram.

Y4 -- Identify, classify and sort a range of triangles.