algebra precalculus - PEMDAS:How to solve this exercise?

I have the following problem:
$$100*\left\{24+100*[1001-4*(25*6+25*4)]\right\}$$

I'm very frustrated that I can't solve exercises like this. I have read about PEMDAS and followed the steps but somehow I am making a mistake because the result I get is not correct.(looked at answers in the book).

Can someone provide the steps in order to solve correctly this problem?

Answer

First, do the innermost products, $25*6$ and $25*4$. Then add them. Then multiply the result by $4$. Then subtract this from $1001$. Then multiply the answer by $100$. Then add $24$. Then multiply the result of that by $100$.

Or:

1. You will need to multiply $100$ by the result of what is in curly brackets;

   
   
   
   
   
   

   • What is in curly brackets requires you to add $24$ to the result of multiplying $100$ by the answer you get from inside the square brackets;

     
     
     

     -What is inside the square brackets requires you to start with $1001$, and subtract the result of multiplying $4$ by the result of what you have inside the round parentheses.

     
     
     
     
     
     • To compute what is inside the round parentheses, you first do the products ($25$ times $6$ and $25$ times $4$), and add them.
     
     
   
   

Now "unfold" that to get the answer.