Let me help you with this! Please make sure you have set the volume used for spreading to 0.1 mL. For the dilution factor choose the value that you can see in the tool tip for the agar plate that you are using for counting. All you need to do then is to count the colonies and add the number in the first input box. The correct value for this one is 160,000 cfu/mL. Try again for the next agar plate.