Number Crunching

Here are a few number based puzzles for you.

Counting my thumbs as fingers, I have 11 fingers. How did I work that out?

4 - 1 = 5

11 / 2 = 6

10 + 1 = 9

4 * 2 = 9

12 / 2 = 7 (and 7 * 2 = 12)

Math puzzles are always out of my head.

Dwarf said:

Here are a few number based puzzles for you.

Counting my thumbs as fingers, I have 11 fingers. How did I work that out?

4 - 1 = 5

11 / 2 = 6

10 + 1 = 9

4 * 2 = 9

12 / 2 = 7 (and 7 * 2 = 12)

Thats an easy one ... you lost one to a dwarf maiden during a particularly nice evening at the local pub....

H2SO4 said:

Since I don't get that one, I'll contribue a different puzzle:

a = 1
b = 1
a = a
a = b
ab = a^2
ab - b^2 = a^2 - b^2
b(a - b) = (a + b)(a - b)
b = (a + b)
1 = 1 + 1
1 = 2 <--- eh?

Where's the logic flaw?

Division by zero:

(a-b), both sides

?

For the original question

Count down the digits on left hand 10-9-8-7-6 then add the right hand

6 + 5 = 11

Barman58 said:

For the original question

Count down the digits on left hand 10-9-8-7-6 then add the right hand

6 + 5 = 11

Smarty pants!!

j/k

For my other puzzles here, this is an indirect clue.

Complete the following well-known saying:

When in ???, do as the ??? do.

Ah I see now said the blind centurion

Was he waving his wooden leg in the air?