Have you ever tried to help a child with their third-grade math homework, only to find yourself stumped? You’re not alone. Many adults are surprised to discover that some of the math concepts taught to third graders can be downright perplexing. Let’s take a trip back to elementary school and explore these 14 math concepts that might leave you scratching your head. Who knows, you might just learn something new!
1. Multiplicative Comparisons

Multiplicative comparisons can be confusing because they require you to view numbers in relation to each other, rather than as standalone figures. Instead of asking, “How much more is this than that?” you’re now wondering, “How many times more is this than that?” For example, if one tree is 5 times taller than another, it requires a shift in thinking compared to addition. According to Robert Siegler, a professor of psychology at Carnegie Mellon University, understanding these comparisons is crucial for developing a deeper number sense. It helps kids and adults grasp the concept that numbers exist in a complex web of relationships, not in isolation.
Trying to visualize these comparisons can be tricky, especially if you’re not used to thinking in terms of multiplication. It’s not just about memorizing multiplication tables; it’s about understanding the scale and ratio between numbers. As kids, we learned this through visual aids like graphs and number lines, but as adults, these tools aren’t always at our disposal. So, next time you’re faced with a multiplicative comparison, try sketching a quick chart or using objects to map it out. It might just make the concept a little clearer.
2. Area And Perimeter

Area and perimeter are two sides of the same coin, but they measure entirely different things. While area calculates the space inside a shape, perimeter measures the distance around it. Many adults struggle with remembering the formulas, let alone applying them to real-life situations. It can be especially confusing when shapes get irregular, and you have to divide them into standard shapes to calculate the total area. When was the last time you needed to know the perimeter of your living room—or the area, for that matter?
For third graders, these concepts are often taught using simple shapes like rectangles and squares. But as you move into more complex figures, the math isn’t as straightforward. Adults might find it embarrassing to admit they can’t recall these basic principles, but the truth is, it’s easy to forget things you don’t use often. So, if you’re trying to solve for area or perimeter, dust off those old math formulas and give them another glance. They might just come in handy during your next DIY project.
3. Fractions As Numbers

Fractions can be a nightmare, right? For third graders, the concept of fractions as actual numbers, not just parts of a whole, is groundbreaking. This is when students start to learn that fractions can represent quantities less than one, more than one, or exactly one. According to Dr. Linda Gojak, past president of the National Council of Teachers of Mathematics, fractions are often the first significant hurdle in mathematics education. They are foundational for understanding more advanced topics like ratios, percentages, and decimals.
Adults might remember fractions as one of those things you just had to memorize, like “one-half” or “three-quarters.” But understanding them as numbers that can be added, subtracted, multiplied, and divided is a whole different ball game. This can be especially challenging when it comes to comparing fractions with different denominators. So, the next time you’re slicing a pizza, think about fractions as more than just pieces of a pie. They’re a versatile part of your mathematical toolkit.
4. The Commutative Property

You might have heard of the commutative property in passing, but what does it really mean? In simple terms, it’s the idea that the order of numbers in addition or multiplication doesn’t affect the result. For instance, 3 + 4 is the same as 4 + 3, and 2 x 5 is the same as 5 x 2. This concept is incredibly useful in making calculations easier, but it’s often taken for granted. We apply it in everyday math without even thinking about it, but explaining it to a child is another story.
Children are encouraged to understand this property through hands-on activities and visual aids. Adults, on the other hand, often rely on rote memory, which means the understanding of “why” can be lost over time. This property is a building block for algebra, even though it seems so simple. If you can’t remember the last time you applied the commutative property, try working it into your next mental math challenge. It’s one of those little tricks that can make numbers a lot more manageable.
5. Understanding Place Value

Place value can seem like second nature—until you’re asked to explain it. This concept teaches that the position of a digit in a number determines its value, which is foundational for understanding any numerical system. It’s more than just knowing that in the number 345, the “3” is in the hundreds place; it’s about understanding that it represents 300. Dr. Jo Boaler from Stanford University emphasizes that a strong grasp of place value is crucial for mathematical fluency. It’s the gateway to understanding more complex operations like multiplication and division.
Adults might find themselves stumbling over place value when dealing with larger numbers or when trying to teach it to children. It involves a mix of counting, estimation, and mental arithmetic that we often take for granted. When was the last time you thought about why shifting a digit to the left multiplies its value by ten? The next time you’re faced with a tricky math problem, take a step back and consider the role of place value. It might just simplify things.
6. Basic Division

Basic division is one of those skills most of us learned in school but rarely think about anymore. It’s the process of splitting into equal parts or groups, and it’s crucial for understanding fractions and ratios. Many adults recall the long-division method from school, but that’s not always the most intuitive way to solve a problem. Often, we forget that division is essentially finding out how many times one number fits into another. As simple as it sounds, the concept can be challenging to grasp, especially if you’re explaining it to a young learner.
For kids, division often starts with simple word problems and progresses to dividing larger numbers. For adults, the relevance of division comes into play when dealing with budgets, sharing resources, or even in cooking. Knowing how to divide quickly and efficiently is a handy skill, but it’s easy to lose touch with it if you don’t practice regularly. Next time you’re in the kitchen halving a recipe or budgeting your monthly expenses, you’ll appreciate the importance of division.
7. The Associative Property

The associative property may sound complicated, but it’s a simple concept that’s easy to overlook. It states that when adding or multiplying, the way numbers are grouped doesn’t change the result. For example, (2 + 3) + 4 equals 2 + (3 + 4), and the same goes for multiplication. According to Dr. Keith Devlin, a mathematician at Stanford University, understanding this property is essential for developing problem-solving skills. It allows students to recognize that they can rearrange numbers to make calculations easier, a skill that’s valuable for mental math.
In practice, adults might not consciously apply the associative property, but it shows up in simple tasks like balancing a checkbook or calculating a tip. It’s easy to overlook this property because it seems so intuitive, but explaining it to someone without using numbers can be surprisingly difficult. If you’re struggling to remember what the associative property is all about, try performing a few mental calculations. You’ll find that this simple rule can make math a whole lot easier.
8. Understanding Patterns

Patterns are all around us, and recognizing them is a skill that’s taught as early as third grade. Whether it’s a sequence of numbers, shapes, or colors, identifying patterns helps in predicting what comes next. For adults, patterns might seem trivial, but they’re the basis for more advanced mathematical concepts like sequences and series. Remembering how to identify and extend patterns might not seem like a big deal until you’re faced with a problem that relies on this skill.
Teaching kids to recognize patterns often involves the use of visual aids and engaging activities. For adults, the concept can be a little rusty, especially if you haven’t had to identify a pattern since school. However, patterns are not just limited to numbers; they appear in day-to-day life, like in music, art, and even in nature. The next time you’re organizing a playlist or planning a garden, try to spot the patterns. They might just inspire you in unexpected ways.
9. Money And Time Problems

Money and time are two things we deal with every day, yet solving problems involving them can be surprisingly complicated. Third graders start learning how to make simple money calculations and read clocks, skills that are foundational for financial literacy and time management. These problems often require the application of addition, subtraction, multiplication, and division, all wrapped up in real-world scenarios. For adults, the challenge is often in the precision and attention to detail that these problems demand.
Teaching kids about money often involves using fake bills and coins, while time-telling can include engaging, interactive clocks. As adults, we’re expected to have these skills down pat, but that’s not always the case. It’s easy to make errors in budgeting or to miscalculate time, especially when life gets hectic. If you find yourself challenged by these everyday math problems, revisit the basics. A little practice can go a long way in improving your financial and time management skills.
10. Rounding Numbers

Rounding numbers might seem like a simple concept, but it can trip up even the best of us. It involves finding the closest number at a given level of precision, which is a skill often used in estimating and simplifying calculations. For third graders, rounding is typically limited to the nearest ten or hundred, but as adults, we often round to suit various contexts. Whether it’s for calculating tips, taxes, or making quick estimates, understanding how to round effectively is crucial.
Teaching rounding to kids usually involves number lines or rounding rhymes to make the concept stick. Adults might remember the basic rules but forget the nuance involved, especially when dealing with decimals and larger numbers. Rounding can be particularly important in fields like finance and engineering, where precision is key. If you’re ever in doubt about how to round properly, take a moment to review the rules. It could save you from making costly mistakes.
11. Using Number Lines

Number lines are a visual tool that can make complex math concepts more digestible. They help illustrate everything from basic addition and subtraction to more advanced ideas like fractions and decimals. For children, a number line provides a concrete way to visualize abstract numbers, making it easier to understand their relationship to one another. Many adults dismiss number lines as elementary, but they can be incredibly helpful for tackling more complex problems.
In the classroom, number lines might be colorful and interactive, turning math lessons into fun activities. For adults, revisiting this tool can be enlightening, especially if you’re struggling with mental math or trying to explain a concept to a child. If you haven’t used a number line in years, it might be worth giving it another look. It’s a simple but powerful way to bring clarity to complicated calculations.
12. Understanding Graphs

Graphs are everywhere in today’s data-driven world, yet understanding them is a skill that stumps many adults. From bar graphs to pie charts, these visual tools aim to make data more accessible. When you’re in third grade, learning to read and interpret graphs is an exciting adventure. As an adult, it can be downright daunting, especially when graphs are packed with information.
Teaching kids to understand graphs involves using real-world examples and engaging stories. For adults, encountering graphs in spreadsheets, reports, or presentations can be overwhelming. Understanding how to read graphs can make a big difference in interpreting information, whether it’s in a work report or a news article. If graphs have always been a challenge, take some time to revisit the basics. They can offer insights that words alone cannot provide.
13. Simple Probability

Simple probability is the mathematical way of expressing uncertainty, and it’s taught in an accessible way to third graders. Kids learn to predict outcomes like flipping a coin or rolling a dice, gaining a sense of how likely an event is to occur. Adults often deal with probability in more complex scenarios, such as financial forecasts or risk assessments. It’s a concept we encounter regularly, yet many of us don’t fully understand how to calculate it effectively.
In the classroom, probability is often taught through games and experiments, making it a fun and interactive experience. For adults, understanding probability can be a bit more serious, especially when it involves making important decisions. Whether you’re gambling, investing, or just making everyday choices, a basic grasp of probability can be incredibly helpful. If you’re fuzzy on this concept, try some simple experiments to get a better feel for how it works.
14. Solving Word Problems

Word problems are math’s way of applying numbers to real-world scenarios, and they’re often a stumbling block for students and adults alike. They require not just mathematical skills, but also reading comprehension and critical thinking. For third graders, word problems are a fun challenge that encourages problem-solving. For adults, they often bring back memories of tricky math tests and unanswered questions.
In school, teachers use real-life scenarios to make word problems relatable and engaging. As adults, we encounter word problems in everyday situations, from cooking to budgeting. Solving them requires a blend of skills that aren’t always intuitive. If you’ve ever struggled with word problems, it might be time to practice breaking them down into smaller, manageable steps. You’ll find that this skill is as useful in life as it was in school.
