Writing and reading algebraic expressions

Welcome to MooMooMath today we are going to look at how to write algebraic expressions. This is one of the more difficult concepts students run into. First of all you need to know your keywords and how those translate from English to Math language. Before we jump into these examples, I’m going to zoom over and go over a list of keywords. I have a list of them and they are on our website, so when you have the keywords, increased by, combined with, more than, combined together, some are added to your going to make that into an addition statement. If you have the keywords decrease by, minus, less, difference of, less than, fewer than you’re going to use subtraction. If you see, times, multiplied, product of, increased by, factor of, you will use multiplication, and if you see these keywords, per, out of, ratio quotient, percent you will use division. So let’s go back to our example using our keywords.  So now we have the sum of five and x, so what’s the sum? So using our key words we will use addition, so I will add these two together. I’m just going to add 5 and x together. The order doesn’t matter with addition, but that’s not true with subtraction. So let’s look at the next one. Five less than the number. If I go to my keywords, less means I’m going to subtract, but you have to be careful. The “than” reverses the order that it is written. So I’m going to take a number which I don’t know so that will be my variable, and it is going to be written first, then I’m going to subtract the 5. This expression is actually x-5 not 5-x because of the word “than” reverses these positions . The last one is twenty four per three acres. Per means division so I’m going to have twenty four divided by three and that’s how I would write that expression. Look for part two for more examples and a little more help. 

Algebra is a language that uses letters, symbols, and numbers to express relationships. In order to write algebraic expressions it helps to know the key words and their algebraic definition. Learning these key terms helps one to write and read an algebraic expression that includes a variable. Remember a variable is simply a letter that takes the place of a number.Here is a list of the common key words to used in Algebra.

Examples of Writing Algebraic Expressions

Example Problem 1 Examples of Algebraic Expressions
Rewrite the ratio of x and 4 into an algebraic expression.
Ratio means division so …. it becomes x÷4 or x⁄4
 
Example Problem 2 Writing Algebraic Expressions
How would you rewrite 5 less than a number in an algebraic expression?
The less than equals subtraction so it becomes ……… x-5
 
Example Problem 3 Algebraic Expressions Examples
Rewrite 24 per 3 acres into an algebraic expression.
per equals division so it becomes…. 24 ÷3=