# 02 - Introducing Number Systems

1. What is our 'western' current number system called and what 'base' is it?
`Interesting fact: It may surprise you to know that the way we 'count' and do mathematics is not necessarily the same in different cultures.`

Decimal, Base 10

Octal, Base 8

Binary, Base 2

Babylonian, Base 60

2. What does the 'base' of a number system refer to? (e.g. Base 10 for the Decimal system means….)

…that the number system can add numbers up 10 times

…it is just a number, it doesn’t mean anything

…it is a number that tells us how many years it took for the system to develop (e.g. 10)

…that there are 10 digits in the number system, e.g. 0,1,2,3,4,5,6,7,8,9

3. Binary is a base 2 system which means….

It has two digits in use - 0 and 1

It has two digits in use, 1 and 2

It goes up to the number 'two' - so the numbers are 0,1,2

None of the above

4. Octal is a base 8 system which the yuki people used. What statement is true?
`Note: if you are able to, this video is well worth a watch. `

It has eight digits, 0,1,2,3,4,5,6,7

Numbers above 9 cannot be comprehended by the people using this number system

It has eight numbers starting from 8 and going up to 16

It can only add up in groups of eight, and cannot understand anything that goes over 9

5. So, what really is a number? Think about the number 675 in decimal- what does it mean?

The number 675, has six 'one hundreds', seven 'tens', and five, ones.

The number 675 in decimal has six lots of '6', seven lots of '7' and five lots of '5'.

The number 675 has 675 lots of one hundred

None of the above

6. The following diagram shows the place values for the number 675 in decimal (base 10). How do we get the place value 1000?

10 to the power of 10 would give us 1000

10 to the power of 3 would give us 1000

None of the above

10 to the power of 1000 would give us 1000

7. Have a read of the 'fact' on the image below. Is it true or false that the ancient babylonians used base 60?

False

True

8. The following binary number (in green) is ______ in Decimal?

12

5

3

2

9. Looking at the table below, what statement is true about the Hexadecimal number system?

The table shows that it has numbers and letters as part of the system and this cannot be possible

The table shows that it has 16 digits. A in Hexadecimal is A in Decimal

None of the above

The table shows that it has 16 digits 0 to 9 and A to F. F in Hexadecimal is 15 in Decimal

10. Here is an image showing the mayan number system. What base number system is it?

20

19

2

10