Axioms of Real Numbers

Definition of Axioms of Real Numbers

Axioms are like the basic rules that all players agree to follow before starting a game. For real numbers, these axioms are the core rules that they stick to. Real numbers are all the numbers that we normally use, like 1, 2, 5.5, or even the square root of 9. However, real numbers do not include square roots of negative numbers because those are imaginary numbers.

Imagine playing chess and not knowing how the pieces move – you wouldn’t get very far. Axioms are the chess piece movements for numbers. They are the starting point that no one doubts. We don’t prove these rules with other facts. We simply take them as the starting point of math. Rather than using axioms like tools, we recognize them and apply their truth when we face math problems.

Axioms aren’t a ‘how to’ guide that you learn to follow. Think of them more like the ground we walk on – always there, supporting every step in math, even when we don’t notice it.

Types of Axioms of Real Numbers

  • Commutative Axioms: These explain that swapping the order of numbers doesn’t change their sum or product. It’s like saying whether you put on your left shoe or your right shoe first doesn’t matter – you end up wearing both anyway.
  • Associative Axioms: These say that how you group numbers when you add or multiply them doesn’t change the outcome. Think of it as putting on socks then shoes or shoes then socks – either way, you’re fully dressed for your feet.
  • Distributive Axiom: This shows us how to spread out multiplication over addition. It’s like handing out equally the slices of a big pizza to a group of friends. Each person gets the same amount, no matter how you split it.
  • Identity Axioms: These identify special numbers in addition (0) and multiplication (1) that keep other numbers the same. It’s like adding zero stickers to your collection – you still have the same number of stickers, or multiplying your sticker count by 1 – it doesn’t change.
  • Inverse Axioms: They tell us about the numbers that can reverse the effect of other numbers through addition (negative numbers) or multiplication (reciprocals). Like if you take 5 steps forward and then 5 steps back, you end up where you started.

Examples of Axioms Of Real Numbers

  • Commutative Axiom for Addition: 3 + 4 is the same as 4 + 3. It’s like saying whether you get 3 apples then 4 oranges, or 4 oranges then 3 apples, you still have 7 fruits in total.
  • Commutative Axiom for Multiplication: 2 * 5 is the same as 5 * 2. Think of it as having 2 bags of 5 marbles each or 5 bags of 2 marbles each, either way, you get 10 marbles total.
  • Associative Axiom for Addition: (1 + 2) + 3 is the same as 1 + (2 + 3). If you get $1, then $2, and finally $3, or get $1, pause, and then get $2 and $3 together, you still end up with $6 in your pocket.
  • Associative Axiom for Multiplication: (2 * 3) * 4 is the same as 2 * (3 * 4). Say you double a triple amount of cookies and then multiply by 4, or you double the cookies and then quadruple a tripled amount, you still have the same mountain of cookies either way.
  • Distributive Axiom: 2 * (3 + 4) is the same as (2 * 3) + (2 * 4). It’s like if you have 2 bags and put 3 toys plus 4 toys inside versus putting 3 toys in both bags and then 4 more toys in both, the amount of toys in the bags stays the same.
  • Identity Axioms: For addition: 6 + 0 = 6. Adding nothing doesn’t change the amount, just like if your score in a game is 6 and nobody scores, you still have 6 points. For multiplication: 7 * 1 = 7. Multiplying by one is like having a clone machine that makes a clone of you – there’s still just one of you.
  • Inverse Axioms: For addition: 5 + (-5) = 0. It’s like having 5 candies and then eating 5 candies – you end up with no candies. For multiplication: 4 * (1/4) = 1. If you have a pizza and cut it into 4 slices and then take one slice, you essentially have a quarter of your pizza.

Why is it Important?

Knowing the axioms of real numbers is super crucial – they are the rules that keep math fair and consistent. Without them, doing math would be like trying to play a game where everyone makes up different rules. These axioms lay the foundation for harder math. Just like you need a strong base to build a sturdy house, these rules give us a firm ground for all of math.

Think about this in everyday life. When you split a pizza among friends or share the cost of a gift, you’re using these axioms without even knowing it. They help you make sure everything is even and fair – nobody gets too much or too little. And when it comes to jobs like architects designing buildings or scientists creating medicines, they all rely on the axioms to make accurate calculations.

Related Topics

  • Fractions: Even though they might seem different, fractions follow the same axioms. They play by the same rules when you add, subtract, multiply, or divide them.
  • Decimals: Just like whole numbers, decimals also stick to these axioms. Whether you’re dealing with money or measurements, the axioms guide how decimals behave.
  • Linear Algebra: As we venture into more complex math, like working with vectors and matrices, we still see the influence of these axioms. They form the base of more advanced concepts in math.
  • Calculus: Even when you dive into calculus, studying how things change, the axioms are still at play, ensuring everything works out as it should.


In conclusion, think of the axioms of real numbers as the basic, no-brainer rules that we follow all the time in math. They may sound fancy, but they’re truly simple at heart. Whether you’re adding up your allowance or figuring out a tough equation, these axioms are the silent heroes making sure everything adds up correctly. They are the unsung foundation that holds up the vast world of mathematics, science, and much of the world we know.