You may have heard of a numerical expression, but have you heard of a algebraic expression?
Numerical and algebraic expressions both have numbers and operations, but algebraic expressions include one more thing, variables.
Variables are numbers that are written down as a symbol. You probably heard of x, y, a, c, and etcetera, which are all letters from the alphabet. Variables do not have to be letters, although they are more common. A star could also be a variable. These letters are used a placeholder for varying expressions and quantities, which is why they are called a variable. A algebraic has at least one or more variables.
IMPORTANT: Keep in mind that both numerical and algebraic equations DO NOT have equal signs. When a group of numbers and operations do have a equal sign, they are called a equation.
Now, let’s test your knowledge before we get on to the more complicated information.
What type of expression is this?
2+4+1 1. Numerical
2. Algebraic
Got the answer? If you chose the numerical expression…you are correct! This expression has only numbers and a operation, addition!
Ready? Here’s the next question:
100+9x 1. Numerical
2. Algebraic
Do you have your answer? The answer is….algebraic! This expression has numbers, the operation addition and multiplication, and the variable x!
You may be wondering where the operation multiplication is. In 100+9x, the multiplication is between 9 and x. So why is there no multiplication symbol? X and the multiplication symbol, × ,are very similar and can be confusing when next to each other. So instead, we put the variable next to the number. Example: 8w, 10p, 4y
However, there is a problem with this solution. If you put two numbers like 2 and 4 together, it would look like 24. So, we came up with another solution just for numbers. Instead of putting the numbers next to eat other, we can use a dot, ⋅.
NOTE: The dot can also be used with variables.
Example: 2 ⋅3, 4 ⋅ 10, 4 ⋅ x
Another way of showing multiplication is by parenthesis. Examples: 6(5), 7(5), 3(y).
So you have the dot, ⋅ , parentheses, ( ), and numbers and variables next to each other, 8w, all symbolizing multiplication. Make sure to remember all of these because different apps and schools will write the multiplication symbol in these three different ways.
That’s it for this article! I will post a post another article about simplifying and solving equations and expressions soon. This article may be very easy or hard for some people, so email me at shannonkaho@gmail.com if you have any questions or requests. Until next time!
Ryan
Yes in code * means multiply….Console.WriteLine(“hello there”);
Steve
That is so detail. I have a headache now. U can also user the asterisk (*) to represent the multiplication symbol.