I would like to extract a number from $0 and calculate if it can be devided by 25. Though the number can also be less then 25 or bigger than 100. How do i extract the number and how can the integer be calculated?
Your question may be too specific. "all_results">39</span> is not your input data, and the manner you use to strip it out may not be ideal or even reliable. Without seeing your actual input it's difficult to improve on it.
Once you get the number, you can easily enough test if things divide evenly with the modulus operator, %. It gives the integer remainder when divided by something. 101 % 25 would be 1.