Standard Deviation - In Plain English?

Question

If a student scores one standard deviation above the mean on Test A and two standard deviations below the mean on Test B, how do I explain the results in plain English (i.e. to her family)?

Answer 1

Sally did very well on test A, but was near the bottom on test B.

Answer 2

you should know
at mean that mean you are 50%
1 stdev is 68% bell curve
2 stdev is 95%
3 stdev is 99.7%

first test 1 stdev 68/2 + 50 is 84% better than class
second test you score 50 - 95/2 = % better than class