A key skill required to pass the exam is the ability to perform calculations without making mathematical errors. Many problems are missed due to “fat-fingering” the calculator, forgetting to divide by 12, or adding instead of subtracting. These mistakes are easy to make, it can happen to anyone! But you can’t afford to miss problems due to math errors, you should only miss problems that you don’t know how to solve! Here at PE Prepared, we encourage test-takers to make tables to simplify the number of calculations required for any given problem.
As an example, many hydraulics problems require you to calculate the area of a pipe given its radius or diameter. Why take the chance of calculating the area from the radius and converting from inches to feet, etc. every time? Every time you perform a calculation on your calculator, you open yourself up to the possibility of making a mistake. Instead, create a table before the test with the corresponding area of all of the nominal pipe sizes flowing full, given in inches and feet. That way during the test you can skip an entire step, you see 6-inch diameter pipe, you just look up the area as 0.1963 square feet and you are off to the races! You can thank us later.
PE Prepared has developed a few tables for common calculations that are available here to download:
Cross-Sectional Areas of Standard Nominal Pipe Sizes
Flow Through a 90-Degree V-Notch Weir
Capacity of Standard Nominal Pipe Sizes Flowing Full
Cross-Sectional Area of Trapezoidal Channels
Typical Flowrate Unit Conversions
Hydraulic Radii of Trapezoidal Channels
Rankine Active Earth Pressures
Velocities in Standard Nominal Pipe Sizes Flowing Full (gpm)
Velocities in Standard Nominal Pipe Sizes Flowing Full (cfs)