Probably 2 1/4 pounds or 2.25
If the recipe calls for 4 1/2 pounds of chicken and you need to half it, it's pretty simple to figure out:
4 divided by 2 = 2 and 1/2 divided by 2 = 1/4
Since it looks like K12, try going through the lesson if you're struggling with it! Also try using outside sources such as videos.
Have a great day!