I am having a hard time on approaching this code challenge

This one can be really intimidating at first, but if you break down the problem it becomes a lot easier to approach.

First, you need to split the word in half. Then you need to lowercase the first half, and uppercase the second half. Finally, you combine the first and second half and return it. All of this is done in one function that takes in a string.

So you've got the function setup to take in one argument, so that's the first step solved. Next, you'll need to split the word in half. Keep in mind, you won't know the length of the word ahead of time. To do this, you'll use slices, which you've been learning about in this course. With slices, you need to use whole numbers. To make sure you get a whole number when finding the length and dividing it in half you'll want to either use int() which will round the result to the nearest whole number or (edit) integer division // which does the same thing. So how would that look?

example_word = "Treehouse"
len(example_word)   #would return 9
int(len(example_word)/2) #would return 4
first = example_word[:int(len(example_word)/2)] #would store "Tree"

Next, you just need to use some tools from past lessons upper() and lower().

# continued from above example
lower = first.lower() #would store "tree"
upper = first.upper() #would store "TREE"

Then just combine the two strings in your return.