why do we need an order of operations agreement

The purpose of this task is to help students think about the reason for the mathematical convention known as the "order of operations. " The task could be used in two ways: to present an apparently unresolvable mathematical situation that can lead to a classroom discussion about the need for an order of operations, or to help students who know already know the order of operations to pause and think more deeply about why they are necessary. For students to get the full benefit out of this task, they will need to hear a bit more from the teacher about the idea of mathematical conventions and why we need to have them when a mathematical statement would otherwise be ambiguous. Addition, subtraction, multiplication, and division are all operations that take two numbers (named the addends, the minuend and subtrahend, the factors, or the divisor and the dividend, respectively) and produce a single number (called the sum, the difference, the product, or the quotient, respectively)--this is why they are called
binary operations.


In principle, grouping symbols are needed whenever there are more than 2 numbers that will be combined using one or more of these binary operations. This is because it is impossible to know a priori whether, for example, means we should add the 8 and the 3 first, which seems reasonable since in many languages, including English, we read from left to right, or multiply the 3 and the 2 first. In mathematics, we resolve the meaning of numeric expressions that include more than two numbers but do not contain grouping symbols in one of two ways: We convince ourselves that, in some instances, the result is the same regardless of which pair of numbers we choose to combine first.


We choose conventions for the order in which we evaluate a numeric expression because we will get different results if we simplify the expressions in different ways. are examples of the first of these. The so-called "order of operations" are how we have settled the second of these. To go back to our original example, we know that because we have all agreed that if we have an expression with at least three numbers that are combined using addition and multiplication, we will multiply before we add. There are actually some good mathematical reasons we have structured the order of operations as we have; to read more about it, see by H. Wu. If + precedes * x then 2+3x4 = 20 and 2+(3x4) = 14. You are allowing your built-in habits to cloud your objectivity.


We are so accustomed to the usual rules that it s hard to see alternatives. In fact computer scientists and logicians,have alternate notational systems such as in which the operators go first. In prefix, + 2 3 is 5. And then + * 3 4 2 would be 14. You are working inside out, and the order of operations is determined by the order in which the operators appear. One argument I can think of in favor of the usual rules is that in algebra, multiplication distributes over addition. For all real numbers a, x, and y, we have a(x + y) = ax + ay. If we put addition before multiplication, what would that be? a x + y = (ax) + (by). Looks weird but we d get used to it, so I don t think this supports either side. Whatever they taught us as children, we d just internalize.

  • Views: 31

why do we use the order of operations in math
why do we use order of operations
why do we need order of operations in math
why do we have order of operations in math
why do we need an order of operations agreement
why do we need order of operations in math
why do we need order of operations