Converting Decimal to Binary and Binary to Decimal

Just learned a new trick from a colleague on how to convert decimal to binary and vise versa.


Determining the difference of binary with decimal:

• BINARY is the representation of number using only two digits, 1 and 0 (e.g 00001, 01001).
• DECIMAL are numbers in base 10 (e.g. 1, 2, 4, 8, 16, 32, 64, 128, 256, 512).

Determining the decimal values in the fingers:

The values of each finger from the left index to the left pinky is the exponents of 2 (from 1 to 10). The right thumb contains the starting value which is 1.

Determining the binary values in the fingers:

Also, remember that 0 means off (deactivate) and 1 means on (activate).

Some examples:

1. Convert the decimal number "2" into binary digit.

The decimal value "2" is located at the right index therefore, activate "2" by opening your right index (don't mind the left fingers yet). Since it is the only number to be converted, then, the other fingers must be deactivated or closed. You now have 00010 as the binary of "2". (See image below.)




2. Convert the decimal value "6" to binary digits.

The decimal number "6" do not appear in the exponents of 2. So, you must have to add the answers of the exponents of 2 which are 2^1 = 2 and 2^2 = 4. 2 and 4 is equal to 6. Activate 4 and 2 in the positions of decimals in your finger, that would be 4 in the middle finger and 2 in the index. You now have 00110 as the binary value of "6". (See image below)





3. Convert the decimal 7 to binary.

1 (right thumb) + 2 (right index) + 4 (right middle finger) = 7. Activate your right thumb where 1 is located, activate the right index where 2 is located, activate the right middle finger where 4 is located. The other fingers must be deactivated.



Converting Binary to Decimal:

Always remember to start activating fingers from left to right so that if the given the binary value 10001101, then activate: right thumb, right middle finger, right ring finger and left middle finger and deactivate others. Now, add the the decimal values equivalent to the fingers that would make 131.