Mathematics on the campus: the “degree-tree” in Tanzania

Mathematics in the daily news:elections in South Africa (April 1994)

How many elephants?

Example from ‘Comparing Quantities’

T-shirts and cola:solutions 1

T-shirts and cola:solutions 2

T-shirts and cola:solutions 3

• teaching-techniques.doc

Example from Ghana SSS Mathematics 3, page 124

On pairs of similar figures.

The area of ∆ ACD = 64 cm2. Find the area of ∆ ABE.

4 cm

6 cm

5 cm

12 cm

A

B

E

DC

The Legend of the Tower of Hanoi (or Brahma)

Legend says that at the beginning of time the priests in the temple were given a stack of 64 gold disks, each one a little smaller than the one beneath it. Their assignment was to transfer the 64 disks from one of the three poles to another, with one important restriction: a large disk could never be placed on top of a smaller one. The priests worked very efficiently, day and night. When they finished their work, the myth said, the temple would crumble into dust and the world would vanish.

How long would this take, assuming that one move would take an average of 1 second?

The rules:

1) In every move, you can only move one disc to another peg

2) You may never place a bigger disc on a smaller one

3) All pegs may be used

Tower of Hanoi

Summary

• Use real world problems as a starting point.• Connect to pupils’ current knowledge.• From informal through preformal to formal.• Take enough time for each step. • Use own productions.• The formal level of one stage can be used as an

informal introduction to the next stage.