Idea 160: Maths Mental-Oral Starter Activity

An easy low-resource idea from a seminar I attended, designed to encourage reasoning and higher-order thinking through discussion of mathematical terms.

Give the class a list of statements about shapes (or whatever else you are studying). They have some time to think about the statements individually first, then they can work through in pairs or small groups and argue whether they think the statements are always true, always false, or sometimes true. You can have a discussion as a class after pair work and see which points were proved easily and which took a bit of work to find the answer.

Example statements (my comments on them in italics):

You can make a square out of four triangles.

I proved this by making a square out of two rectangles and then splitting each rectangle diagonally, making 4 triangles. Many other people in the seminar just took a square and divided it up with two diagonal lines to produce four triangles.

A pentagon has 4 sides.

This is an interesting question as technically a pentagon does have 4 sides, as well as one more!

An octagon has 8 sides.

A square is not a rhombus.

A square is a rhombus, it’s actually a special type of rhombus where opposite angles are equal.

A cube has six square faces.

The sum of interior angles in a triangle is always 180.

Three squares put together can make a bigger square.

If you cut up a square into two different pieces, they will be of different sizes.

 

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3 Responses to Idea 160: Maths Mental-Oral Starter Activity

  1. appmothers says:

    Reblogged this on h App y Mothers and commented:
    I love your activities, Michael. Keep the creative juices flowing

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