Units are not returning correct answer

Without seeing what you're doing, we can only guess.

If you have an emperical equation with a "constant" in it (old engineering Handbooks were great at this) there's a chance that that constant is really a unit conversion factor.  Since Mathcad is "unit aware," it will translate units for you, so to calculate power (in watts, kilowatts, or horsepower, or any other unit of your choice) you multiply torque times angular velocity, and Mathcad takes care of the unit conversion for you.  (No P = T w/5252 because T is ft lbf and w is rpm.)

The other possibilities include:

• The units are right, but they look wierd.  Try replacing what Mathcad defaults to with the unit you expected.  If it's equivalent all the strange notation will disappear.  If it's not equivalent, Mathcad will add units to make the units balance.  If you expected horsepower and type "hp" and get "hp sec," then you are computing work instead of power.
• You have a unit declaration wrong.  Did you want force, but typed "lb" instead of "lbf"?
• Your Handbook equation cannot unit balance-- it's an empirically derived expression with no physical reality.

If you zip your file, you can attach it.  That gives the rest of the world a chance. . .