Binary Fingers!

Forget about counting to 10 on your fingers ... you can count past 1,000 if you want!

Right Hand

With just your right hand you can count to 31:

Closed fist representing zero
No fingers up is 0
Right hand with only the thumb extended representing one
Thumb is 1
Right hand with only the index finger raised representing two
Index finger is 2
Right hand with thumb and index finger raised representing three
2 and 1
makes 3
Right hand with only the middle finger raised representing four
Middle finger is 4
Right hand with thumb and middle finger raised representing five
Add your thumb
for 5
Right hand with index and middle fingers raised representing six
4 and
2 makes 6
Right hand with thumb, index, and middle fingers raised representing seven
4 and 2 and 1
makes 7
Right hand with only the ring finger raised representing eight
Fourth finger is 8

... and continue the pattern:

  • add your thumb (+1) to make 9,
  • or add your index finger (+2) to make 10
  • or add thumb (+1) and index finger (+2) to make 11
  • and so on

Each finger is worth twice as much as the finger before it: 1, 2, 4, 8, 16.

In fact you are counting in Binary:

Number Made by Right hand with binary place values labeled: pinky is 16, ring is 8, middle is 4, index is 2, thumb is 1
1 1         up
2 2       up  
3 2+1       up up
4 4     up    
5 4+1     up   up
6 4+2     up up  
7 4+2+1     up up up
8 8   up      
9 8+1   up     up
10 8+2   up   up  
11 8+2+1   up   up up
12 8+4   up up    
13 8+4+1   up up   up
14 8+4+2   up up up  
15 8+4+2+1   up up up up
16 16 up        
17 16+1 up       up
  and so on....          

Here are some more examples:

Right hand with pinky, ring, and index fingers raised representing twenty-six
16+8+2
makes 26
Right hand with pinky, ring, middle, and index fingers raised representing thirty
16+8+4+2
makes 30

Why?

So you can count to bigger numbers when you don't have a pencil or paper.

You can also "remember" numbers by holding your fingers in the right way.

Or you can show someone a secret number using just your hand (or hands, see later).

Your Turn

Practice counting from 0 to 31 on your fingers, just like above.

Do it many times until it becomes easy.

When you can do it well, demonstrate it to your friends!

Left Hand

Want bigger numbers? Your left hand can help:

Left and right hands labeled with binary values from five hundred twelve down to one

Now we can use all 10 fingers to make numbers like these:

Left pinky finger (32) and right index finger (2) raised representing thirty-four
32+2
makes 34
Left pinky (32), right pinky (16), ring (8), and middle (4) fingers raised representing sixty
32+16+8+4
makes 60
Both hands with selected fingers raised representing eight hundred three
512+256+32+2+1
makes 803

And last, what happens when all fingers are up?

Both hands with all ten fingers raised representing one thousand twenty-three
512+256+128+64+32+16+8+4+2+1
makes 1,023

So now you can count just past 1,000 using only 10 fingers. Wow.

Practice this over the next few days ... you will gain a new skill and also find binary much easier to understand.

9389, 9390, 9391, 9392, 9393, 9394, 9395, 9396, 9397, 9398
Binary Digits Binary Number System Numbers Index