Originally Posted by

**Junky**
I was the one to advise you in your other post.

Search the web for info about postfix. You should find a algorithm to do it. Why should you change to postfix? Because it makes evaluation so much easier. 1 + 2 * 3 becomes 1 2 3 * +. Then you read the postfix expression. Each time you read an operand you push it onto a Stack. Each time you read an operator you pop 2 values off the Stack, perform operation and push result back onto Stack.

Read 1

Push onto Stack

Read 2

Push onto Stack

Read 3

Push onto Stack

Read *

Pop 3

Pop 2

Multiply

Push 6 onto Stack

Read +

Pop 6

Pop 1

Add

Push 7 onto Stack

Now you have finished reading the postfix expression and the result is the only value left on the Stack: 7.

If this is too much for you then I suggest attempting something simpler.