A. These materials - a set of 48 "shapes" specifically designed to encourage logical thinking - have four different attributes:

Large or small (2)
Thick or thin (2)
Colour - red, blue, yellow (3)
Square, circle, triangle and rectangle (4)

E.g. a large, thin, blue square is different in three ways from a small, thick, red square.

Difference maps can be pre-constructed and children invited to fill the spaces with appropriate shapes. One line means one difference, two lines two differences etc. For example:

example of difference map
example of difference map2

B. Each of the 48 shapes in the set can be described on work cards containing those attributes which list their relevant size, colour, thin/thickness, shape.

two work cards giving egs of shape descriptions

The youngster picks a card, reads it and goes off to find the appropriate shape.