To find the area of a rectangle with length 18 feet and width 5 feet, multiply the dimensions to get 90 square feet.

When you think about math for the HSPT, a lot of it feels like a toolkit you can carry into everyday life. You don’t need to be a math wizard to see the logic—just a few clear steps and a sense for what each number is doing. Let’s start with something simple and really practical: the area of a rectangle. You’ll see how a basic formula becomes something you can use for real projects, like planning a space or choosing the right size rug.

A quick reminder: what is area, anyway?

Think of area as the amount of flat space inside a shape. If you’re laying down tiles, painting a wall, or buying material, area tells you how much surface there is to cover. For rectangles, there’s a straightforward rule, a tidy little formula that helps you get the job done fast.

The rule you need

For any rectangle, area equals length times width. It’s short, sweet, and incredibly reliable. In symbols, Area = length × width. In the real world, you’ll also see units like square feet, square meters, or square inches, depending on what you’re measuring.

Let me explain it with a concrete example

Here’s a clean problem you might encounter, styled like the kind you’d see in a math-focused assessment:

Question:

What is the area of a rectangle with a length of 18 feet and a width of 5 feet?

A. 90 square feet

B. 36 square feet

C. 40 square feet

D. 24 square feet

Take a moment and picture the rectangle: it’s longer in one direction and skinnier in the other. Now apply the formula. Multiply the two numbers that correspond to the sides you’re given:

Area = length × width

Area = 18 feet × 5 feet

Doing the math, 18 × 5 equals 90. Don’t forget the units—since you multiplied feet by feet, the result is square feet. So the area is 90 square feet.

Answer: A) 90 square feet

A few ways to think about it that stick

• Visualize the tile idea: if you wanted to cover the rectangle with 1-by-1 foot tiles, you’d place 18 tiles along the length and 5 tiles along the width. That makes 18 × 5 tiles in total, which is 90 tiles. Each tile is a square foot, so you’re counting square feet.

• Picture a rug: if you’re choosing a rug for a space that's 18 feet long and 5 feet wide, you’d need enough rug to cover 90 square feet.

• Keep the units in mind: if the lengths were in meters, you’d end up with square meters. The trick is to remember you’re measuring two linear dimensions, and you convert that product into a square unit.

Common missteps you’ll want to dodge

• Swapping length and width in your head and ending up with the wrong product. It still works because multiplication is commutative, but it’s easy to second-guess yourself if you aren’t careful.

• Forgetting to include the unit. The math line might read 90, but without “square feet,” you’re missing the context that tells you what you’re measuring.

• Mixing up the idea of area with perimeter. Perimeter is about the edges or the boundary; area is about the inside space. They’re related, but they’re not the same thing.

• Assuming a simple pattern or shape when the problem isn’t that. If the figure isn’t a rectangle, you’ll need a different formula. It’s good to pause and double-check what shape you’re actually given.

Simple tips to speed things up

• Memorize the formula, then practice plugging in numbers quickly. Repetition helps you glide through questions without second-guessing.

• Do a quick mental check after you multiply. If you expected a big space, a 18 × 5 calculation giving 90 square feet feels plausible; if you were expecting something tiny, you’d rethink the numbers.

• Write down units as you go. It’s a tiny habit that saves a lot of confusion later.

• Use estimation for a rough sanity check. For example, 18 is close to 20, and 5 is close to 5, so 20 × 5 gives 100; if your exact product is far from that, you’ve probably made a slip.

Beyond rectangles: a quick shape refresher

Knowing the rectangle area gives you a mental shortcut that extends to other shapes. Here are a couple of quick reminders:

• Square: area = side × side. If a square’s side is s, area = s².

• Triangle: area = 1/2 × base × height. The base and height are the two sides you drop straight down between; the height is the perpendicular distance from the base to the opposite vertex.

• Circle: area = π × radius². If you know the diameter, radius is diameter ÷ 2.

Bringing math into real life

Let’s take a moment to connect this with everyday projects you might actually do. Say you’re painting a wall in a bedroom. You’ll measure the width and height of the wall, multiply those numbers, and get the area in square feet. That tells you how much primer and paint you’ll need to cover the surface evenly. If you’re laying down a carpet or tiles, the same idea applies: you want the area so you know how much material to buy.

And what about a garden bed? If you’re planning to fence it or plant in neat rows, knowing the area helps you estimate how much soil, mulch, or seed you’ll need. It’s a small calculation, but it saves you from buying too much or too little and then doing that awkward math shuffle in the store.

A tactile moment of clarity

Sometimes people feel a bit mystified by math because they picture it as something distant or theoretical. The truth is: area is about space and how we measure it when we’re planning something tangible. It’s the same instinct you’d use when you frame a picture or decide how big a bookshelf should be against a wall. The numbers simply give you a map of the space you’re working with.

Let me share a tiny, human-level digression

Have you ever walked into a room and thought, “Why does this feel off?” It might be the mismatch between the space and the furniture, not the decor. That gut sense often comes from a hidden calculation—how much area you’re dealing with. You don’t need to be a math savant to sense that a room is too cluttered for a sofa, or that you should swap a coffee table for something smaller. Those are area-aware decisions, in spirit if not in name.

A practical mindset for HSPT questions

• Start with what you know: the formula for area is your anchor.

• Check the units last, but don’t skip them. They confirm you’re measuring the right thing.

• When in doubt, estimate first. It keeps you honest about the result you’re expecting.

• Practice with everyday objects. Look around and ask, “What’s the area of this surface?” It turns the abstract idea into something you can see and touch.

A closing thought

The rectangle problem with length 18 feet and width 5 feet isn’t just about choosing A from a list. It’s a micro-lesson in how to translate a real-world scenario into a clean calculation, then translate the result back into something meaningful—like square feet you can use to plan a project. That loop—measure, multiply, interpret—sits at the heart of many math questions you’ll see on tests that value exact thinking and practical sense.

If you’re ever unsure, remember the rhythm:

• Identify the rule (Area = length × width).

• Plug in the values (18 and 5).

• Do the math (18 × 5 = 90).

• State the units (90 square feet).

• Reflect on what the number means in the real world (the space inside the rectangle).

That’s the core of how to approach similar problems with confidence. It’s not a rush to a single correct answer as much as a careful, logical journey from measurement to meaning. And when you recognize that journey—step by step—it becomes a little more familiar, almost like a familiar recipe you can apply again and again.

Bottom line

For the rectangle in our example, the area is 90 square feet. The path there is straightforward: apply the area formula, multiply length by width, and keep an eye on the units. With that approach, you’ll be ready to tackle similar questions with calm clarity—and you’ll see how math quietly weaves into the spaces you design, the rooms you shape, and the projects you bring to life.