Science 122Laboratory 

Doing calculations only seems difficult. If you break it into small steps you will find that none of the steps requires anything difficult. 
Here is a stepbystep guide to evaluation of the relationship for the period of a simple pendulum, as used in lab 5. 
When performing any multistep calculation, write down the appropriate expression at each and every step with the calculated values substituted. It may seem like extra work, but it will keep your thoughts organized. It is easier to enter the numbers into the calculator when they are written down!.
Suppose your length is L = 48.291 cm. Then your relationship would look like this:
For L = 48.291 cm. it would look like this: .
It would look like this:
The number should already be on the calculator display. If it is, simply press the key on the calculator.
If the number has been erased from the calculator display, reenter it, then press the key.
is a number that appears in calculations from time to time. It is the ratio of circumference to diameter of a circle, but it 'pops up' in unexpected places.
There is a key on most calculators. Press the key when you want to enter . If there is not a key, enter the value, 3.14 for .
With the number 0.2219831 still on the calculator display, press the X key, the key, the X key again, then 2, then = .
The result is 1.3947614, which rounds to 1.3948. The unit is seconds.
The calculated result was rounded to the same number of significant figures as the measurement of L. (There are 5 significant figures in 48.291 cm.)
T = 1.3948 sec. when L = 48.291 cm