Math - Fibonacci Sequence

Today I am sick, but I like math so I continued doing what I do for math at school which is the Fibonacci Sequence. The formula for the Fibonacci sequence is Fn-2 + Fn-1. My mum made me do the Fibonacci sequence using the formula, until I reached the twenty-second number in the Fibonacci sequence. At school I had gotten up to the eleventh number in the Fibonacci sequence which was 89, the tenth number was 55, so I had to add up 55 to 89 which equaled 144 (which is my favourite number as it can be multiplied by 12 divided by 12 and is the 12th number in the Fibonacci sequence.) Then for the thirteenth number I did 89 + 144 which equaled 233, Then I did the fourteenth number which was 144 + 233 which equaled 377. See if you can spot a pattern forming, then I did the fifteenth which was 610, then I did the sixteenth number in the Fibonacci sequence which was 987, then I did the seventeenth number which was 1597, then I did the next number in the Fibonacci sequence which was 2584, then I did the nineteenth number which was 4181, then the twentieth number which was 6765, then I did the twenty-first number which was 10946. Finally it was time to do the twenty-second number I add 6765 and 10946 the answer took me about half a minute to figure out it was 17711.