Try this "multi-tasking" exercise
You will need:
A sheet of paper
A pen or pencil
A timer or someone to time you
A sharp mind
Draw two horizontal lines on a piece of paper
Now, have someone time you as you carry out the two tasks that follow:
On the first line, write: I am a great multitasker
On the second line: write out the numbers 1-20 sequentially, like those below:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
How much time did it take to do the two tasks? Usually it’s about 20 seconds.
Now, let’s multitask.
Draw two more horizontal lines. This time, and again have someone time you, write a letter on one line, and then a number on the line below, then the next letter in the sentence on the upper line, and then the next number in the sequence, changing from line to line. In other words, you write the letter "I" and then the number "1" and then the letter "a" and then the number "2" and so on, until you complete both lines. Like this:
I’ll bet you your time is double or more what it was on the first round. You also may have made some errors and you were probably frustrated since you had to “rethink” what the next letter would be and then the next number.