So, we know that 2 1/4 is the normal amount of flour you would use in the recipe. but you don't want to do normal. You want to make 1 1/2 times more than you usually do.
To do this, first figure out what half of 2 1/4 is.
(2 1/4) /2 = 1 1/8
Then, because you are looking to use 1 1/2 times more flour, simply add the 1 1/8 to the 2 1/4
