Base Five Counting ..
If history had taken a different path we could all be using the "Base Five" counting system using one hand for "units" and the other hand for 'higher' place values.
Click here to watch animation again ...
The pattern is the same as with Base Ten, but it is less familiar. Each place is five times the value of the place to the right.
| 125 | 25 | 5 | 1 |
| 3 | 4 | 3 | |
| 3 x 25 = 75 | 4 x 5 = 20 | 3 x 1 = 3 |
ie 343 Base 5 = 75 + 20 + 3 = 98 Decimal
| 125 | 25 | 5 | 1 |
| 4 | 2 | 2 | 0 |
| 4 x 125 = 600 | 2 x 25 = 50 | 2 x 5 = 10 | 0 x 1 = 0 |
ie 4220 Base 5 = 600 + 50 + 10 + 0 = 560 Decimal
The process is the same with all numbers ... to covert to decimal simply add the value of each place to find the total.
Try these ...
1. What finger pattern represents Decimal 9 in Base 5? Click here for the answer ...
2. What finger pattern represents Decimal 26 in Base 5? Click here for the answer ...
3. Work with a partner to draw the Base 5 finger patterns for the following Decimal numbers:
(a) 11 (b) 29 (c) 40 (d) 48 (e) 100 (f) 1001
Have your teacher check your answers when you have finished.
