Who invented PEMDAS? (Order of Operations Timeline Explained)

Quickly now, without using a calculator, try to figure out this quick formula: 50+50-25×0+2+2. Those of you who understand that there’s an order of operation of things will have the answer as 104. There’s no need to fret if you didn’t get that answer, as there’s always room for understanding and growth!

What you’ve just experienced is the importance of the order of operations, also known as PEMDAS. These letters stand for parenthesis, exponents, multiplication, division, addition, and subtraction. So considering the formula above, 25 x 0 is 0, 50+50 is 100, 2+2 is 4, and 100 – 0 is still 100. That leaves 100 + 4 giving us the answer above. Here’s how PEMDAS got its start, and a quick dive into the timeline!

Who invented PEMDAS?

The interesting thing is that no one invented PEMDAS. The order of operations just happened to be the thing that everyone started using. The first time it appeared as a rule was in a Dutch algebra textbook for the military. Eventually, more and more teachers started to use PEMDAS as a teaching tool.

PEMDAS’s key contributors (and evolution)

  • Frans van Schooten
    References the beginning of the order of operations

    Vieta’s collected works under the title of Opera Mathematica had references to the order of operations.

  • Various mathematicians
    The early evolution of PEMDAS

    The Dutch algebra textbook with the explicit rule about PEMDAS was published in 1838. The same thing was repeated in the appendix of another popular algebra book around 1875.

  • G. E. Fisher and I. J. Schwatt
    Further reinforced PEMDAS

    In the algebra textbook authored by G. E. Fisher and I. J. Schwatt, the parenthesis is added to the mix. For example, instead of a ÷ b x b, it’s (a ÷ b) x b.

  • Herbert Ellsworth Slaught and Nels Johann Lennes
    Made further additions to the order of operations

    In their 1907 book (High School Algebra, Elementary Course), it is recommended that multiplications be handled first, and then division from left to right. It makes things easier for the student to figure out the formula without getting too confused in the process.

When was PEMDAS invented?

It’s hard to say when PEMDAS was first invented. However, as far as the first mention of an explicit rule, the very first time the order of operations was added was in an algebra textbook for the military in 1838. Ever since then, constant improvements have been made, though PEMDAS was always an unwritten rule mathematicians followed.

A brief history of PEMDAS

PEMDAS is all about ensuring that people don’t end up with the wrong answer when they try to solve various equations. The interesting thing about PEMDAS is its history and lack of overall documentation — as just about every mathematician knew the rules. PEMDAS back in the day was an unwritten rule that everyone knew. That said, it wasn’t always just going to be the realm of famed mathematicians. The average person would have to make use of the order of operations in their education, which was why it started to appear in various textbooks.

Vieta’s collection of mathematical works by Frans van Schooten is arguably the very first to have some kind of rule similar to what PEMDAS offers. After that came a Dutch algebra book for the military in 1838, which is the first to talk about a concept similar to PEMDAS as a rule of sorts. The little additions in various textbooks continued, and served to convince people more and more to stick to a specific order of operations.

For example, the book of G. E. Fisher and I. J. Schwatt talks about the parenthesis being added to formulas. Herbert Ellsworth Slaught and Nels Johann Lennes talk about multiplying first, and then dividing going from left to right in their algebra book for elementary students.

The thing about PEMDAS is the concept has always been around in one way or another. Mathematicians haven’t made a habit of writing it down, as the order of operations always seems to be an unwritten rule everyone follows. These days, it’s much easier to teach, as just about every school uses PEMDAS.

The PEMDAS timeline

  1. 1646
    Vieta’s mathematical works

    References to the concept of PEMDAS can be found as early as 1646, in Vieta’s collection of mathematical works.

  2. 1838
    The first time the PEMDAS rule is explicitly stated

    A Dutch algebra book for the military contained the first explicit rule relating to PEMDAS.

  3. 1898
    G. E. Fisher and I. J. Schwatt’s book

    The algebra book talked about the addition of parenthesis to various formulas.

  4. 1907
    Herbert Ellsworth Slaught and Nels Johann Lennes’s book

    The algebra book talked about the priority of multiplication, and the order of division.

Where was PEMDAS invented?

Considering the first book to state PEMDAS as a result was for the Dutch military, we can say the concept of PEMDAS was first showcased in the Netherlands. 

The importance of PEMDAS

  • Common sense for just about every mathematician

    There’s a reason why PEMDAS isn’t necessarily well-documented through the years — and it’s because the mathematicians didn’t really need a written order of operations. Everyone already knew how to do it, as common sense dictates a specific order.

  • Ensures students don’t make mistakes

    The cool thing about PEMDAS is how it encourages the proper application of mathematical formulas and builds a healthy habit for those who might not be too interested in mathematics.

  • A surprising amount of variety

    PEMDAS isn’t the only order of operations out there, though it’s the simplest and easiest to learn. There are other types similar to PEMDAS for those who are getting into more advanced algebra and mathematics in general.

  • The best way to teach new students

    The reason why PEMDAS is so important is that it’s the easiest way to teach new students to advanced mathematics. It helps them perform well with much higher odds of success.

PEMDAS by the numbers

  • 1917The year when PEMDAS began to be taught regularly in schools. While it had existed long before, it was more of an unwritten rule than anything.
  • 3There are typically three steps to complete PEMDAS without issues. First and foremost, get started inside the symbols of inclusion (parenthesis, etc.). Second, multiply and divide everything from left to right. Third, add and subtract everything from left to right.
  • 16Symbolic algebra was developed in the 16th century, which also brought about the need for an order of operations.
  • 4The 4th grade is when children are usually taught the basics of PEMDAS. It helps develop a proper foundation for learning.

Five facts about PEMDAS

  • PEMDAS is not necessarily in order

    PEMDAS is usually the easiest way to teach the order of operations, but it’s not necessarily in order. For example, multiplication and division are usually done together, and the same thing goes for addition and subtraction. Unfortunately, PE(MD)(AS) just isn’t as catchy.

  • The full function of the P in PEMDAS

    Keep in mind that the P in PEMDAS doesn’t necessarily mean parenthesis on its own. In just about every formula, any symbol that groups things together (brackets, braces) has the same priority as the parenthesis. 

  • Left to right, and top to bottom

    While most people know to use PEMDAS left to right, compound exponentiation is done top to bottom. It might seem a little complicated, but it gets easier as you go.

  • PEMDAS, simple yet incomplete

    The simple truth of the matter is that PEMDAS is an incomplete explanation when you consider all parts of the order of operations. The more you dabble in advanced mathematics, the more guidance you need to get the job done. Fortunately, PEMDAS does an excellent job of laying the foundation.

  • Constant growth

    PEMDAS isn’t the end-all-be-all of mathematical expression, and things are ever-shifting in the world of mathematics. Fortunately, you can expect any new addition to be part of future mathematical curriculums.


  • What do I need to do to get used to PEMDAS?

    PEMDAS is the simplest way to learn the order of operations. You don’t have to do much except practice! Make sure to tackle the ones inside the brackets and parentheses first, then proceed to multiplication/division and addition/subtraction. It’ll eventually start feeling like second nature!

  • Why is the term PEMDAS so commonplace?

    The simple answer is that it’s the easiest one to teach. Some teachers would even use “Please Excuse My Dear Aunt Sally” as a way to memorize PEMDAS. While it might seem complicated at first, you’ll find that PEMDAS is the easiest way to tackle the order of operations. When it comes to precise algebra, professional mathematicians use more nuanced tactics.

  • Is PEMDAS still relevant?

    That short answer is yes, PEMDAS is still relevant. While it might not be the primary form of mathematical expression, it’s undoubtedly the easiest way to get into the groove of algebra.

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