Mastering the Percentages: A Helpful Guide for Plumbers

When you're gearing up for the Journeyman Plumber Exam, there’s one thing you can bet on: math is going to pop up, especially when dealing with installations and usage percentages. Don't sweat it! Let's break it down with an example that’s both practical and insightful, so you can hit the exam with confidence.

A Little Background on the Gross

First off, let’s talk about what “a gross” means because it can get a little confusing if you’re not familiar with the term. In the plumbing world, or any trade really, a gross equals 144 units. So, when our plumber buys a gross of faucets, he’s picking up 144 shiny new pieces for installation.

The Installation Scenario

Imagine this: you’ve got a grand total of 144 faucets sitting in your workshop. Now, if our plumber installs all but 40 of these faucets, what exactly does that leave us with? You might be thinking, “It sounds like we need to do some math here!” And you’re absolutely right!

To find out how many faucets were installed, we simply subtract the number of faucets not installed from the total. Here’s how it looks:

[ 144 - 40 = 104 ]

Now we see that 104 faucets have been installed. Not too shabby!

Crunching the Numbers: Finding the Percentage

Now comes the part where we calculate the percentage of faucets that were installed. Why is this important? Well, understanding percentages is crucial in plumbing, especially when it comes to making estimations and managing supplies.

So, let’s get to the math. To find out what percent 104 faucets is of the total 144, we need to divide and multiply:

[ \left( \frac{104}{144} \right) \times 100 ]

When you crunch those numbers, you get about 72.22%. Rounding it off gives us approximately 72%. Now you’re probably thinking, “Why is this useful?” Well, knowing that about 72% of the faucets were installed could help in inventory assessments and making informed decisions for future projects.

Practical Applications

You might wonder how this little math lesson connects with real-world plumbing. When you understand these calculations, you can manage your jobs better, plan for future orders, and avoid running into surprises like not having enough materials. Plus, when the inspector comes knocking, you’ll be ready to showcase your knowledge and calculations confidently.

Wrap-Up

To wrap it up, calculating percentages in plumbing isn't just for the classroom; it directly applies to the work you’ll do on-site. From knowing how many faucets are being used to managing your inventory effectively, mastering these mathematical skills will serve you well.

Next time you sit down to study, keep this example in mind. After all, a little math might just be the key to taking your plumbing skills to the next level. So, ready to take on those practice questions? You got this!