I enjoy playing puzzle donkey & i'm a bit late getting around to PD4. So I have no-one around on the usual forums to help. PD4 2.11 is a mth puzzle & I believe the minus signs are used to create a ^ symbol. However I do not know how this symbol works.

The puzzle is below :-

Puzzle 11: Calc-mule-ations

PuzzleDonkey had been given a new set of fridge magnets for his birthday.

He wasn't very excited, though - there was a rather limited range of options.

His set comprised seven of each of the following symbols:

1 + - (

He decided that he'd try and arrange them on his fridge so that they gave the highest possible number.

Of course, it would be cheating if he were to simply combine digits to make larger numbers such as 111 - the largest individual number he'd use was one. He tried rotating a minus to look like a one, too, but that looked well dodgy so he decided against it.

After a week or so, he got bored of the arrangement of magnets on his fridge, so decided to take the equation down. Much to his dismay, a pair of the bracket magnets fell into his carrot dicer and were discombobulated beyond repair.

He presently got his kit out again and aimed to make an equation with the pieces he had left that'd yield the smallest possible positive result.

He wasn't the best at mental arithmetic, so rounded off the outcome to the latter equation to five decimal places, then got out a pen and paper and multiplied this approximation by the larger number he'd generated earlier.

What was the outcome to this little sum?

Please can you give me some hints on what to do & explain the use of the ^ symbol??