III. Answer the questions below and then ask for more information (Work in pairs)

A

1. Who didn’t consider 1 to be a number at all?

2. What number associates with negatives? Why?

3. What number is the dimension of the smallest magic square in which every row, column, and diagonal equals fifteen?

4. What numbers are considered to be perfect in Mathematics? Why?

5. What does the number 7 determine in China?

B

1. In what country is the number 4considered to be unlucky?

2. Why was the number 5 important to the Maya?

3. Why is a knot tied in the form of the pentagram called a lover’s knot in England?

4. What number leads to a few years of bad luck, if you break a mirror?

5. What did students pursue in medieval education?

DO YOU KNOW THAT…

· The number 8 is generally considered to be an auspicious number by numerologists. The square of any odd number, less one, is always a multiple of 8 (for example, 9 − 1 = 8, 25 − 1 = 8 × 3, 49 − 1 = 8 × 6), a fact that can be proved mathematically.

· The early inhabitants of Wales used nine steps to measure distance in legal contexts; for example, a dog that has bitten someone can be killed if it is nine steps away from its owner’s house, and nine people assaulting one constituted a genuine attack.

· The number 20 has little mystical significance, but it is historically interesting because the Mayan number system used base 20. When counting time the Maya replaced 20 × 20 = 400 by 20 × 18 = 360 to approximate the number of days in the year. Many old units of measurement involve 20 (a score)—for example, 20 shillings to the pound in pre-decimal British money system.