If the message area contains what looks like an arithmetic expression:

1 + 3

14/145.98

(2+34)*(2+4+5)

then you can choose Calc (used to be Speak) to have it evaluated and pronounced. You can use SQRT for doing square roots. The letter X is used to remember the result of the previous calculation.

1 + 2 This sets X to 3.

4 * X This will produce 12.

These mathematical functions are also available:

pi

sin

cos

tan

log

rand

int