The Math Crisis of RCDD Candidates

I’ve been teaching ICT courses for a long time now and am continually amazed at the lack of basic math skills exhibited by a significant percentage of both RCDD and OSP candidates.

Let me share some examples of what I see during a typical class.

Ohm’s law – Simple right. I=V/R

Where I = Current, V = Voltage, and R = Resistance

The problem comes, when I ask them to solve for V if I and R are known or solve for R if V and I are known. This is High School math yet many can’t solve for the different variables.

Cross Sectional Area – Another simple one. A=πr2

Where A = Cross sectional area, π = Well pi, and r2 = radius squared

The first problem is a lack of understanding of what constitutes the cross sectional area of a circle/cable. Pi is not normally a problem, but there can be a lot of difficulty in their understanding what the radius of a circle is, not to mention how to square it.


Where N = Need

We’re generally OK at this point and N+1 or N+2 is not usually a problem. We can get through 2N fairly easily, but it all falls apart at 2(N+1) or 2(N+2). The issue is in the correct order of operations. Again, basic High School math.


But, you say, who cares. I never do any of those calculations in my everyday job. And you’d be right, neither do I. But this is an indicator of a more serious problem. Several of my students who had these issues were business owners. How long can they be successful with this gap in their skills.

How about simple tasks like making material lists from drawings. Here’s a scarry example. Back when I was teaching DD102 classes for BICSI, my classes had to complete a final project where they estimated the total material and labor cost for serving a floor in a building. Many of you may remember doing this.

As I remember, the final cost usually came in between $50k and $70k. When I got to the third group in one particular class and asked them for their number…… was $1,000,000. Yes, that’s right, one million dollars.

Well, of course, everyone, including me laughed at first, but when I looked at their worksheet, it was clear that their calculations for the amount of cable needed had no relation to the drawings they were using. And this was not a single student, this was a group of four working on this task and all apparently agreed on the number.

I always spend enough time with my students to make sure they understand these concepts. But, what’s the solution to the bigger problem? Do we need to teach a basic math course? Or, should BICSI test a candidate’s math skills and require a minimum passing score before allowing them to sit for an exam.

Do you know the correct order of operations? Remember PEMDAS:







Let me know your thoughts.

One thought on “The Math Crisis of RCDD Candidates

  1. In the engineering business designers usually come from engineers who have the textbook knowledge, the guy who learned drafting and picked up design along the way or the field guy who proved to be able to pull cable with the best of them and was given a chance to design.
    Assign a percentage to those three scenarios. Now that you have these scenarios and percentages, you tell me why there is a math problem?!

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