You do NOT have to take subject tests at NU - they are recommended, not required. My son got in ED and did not take any subject tests. He called NU admissions and was told that subject tests are only for those that want to show competency in an area that previous classes and tests did not. In other words, if you got a B or a C in an APCalc class, or did not score a 3, 4 or a 5 in an AP test, you might then take a subject test to show that you do know the material. Good luck, but I am sure either school will be good for you.