A written equation can be as simple as "four less than a number is 12." Discover how to break up phrases when writing an equation with help from a math teacher in this free video series on math help and lessons.

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A written equation can be as simple as "four less than a number is 12." Discover how to break up phrases when writing an equation with help from a math teacher in this free video series on math help and lessons.

Part of the Video Series: Math Help

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So, how does one write an equation if you see a bunch of words. Hi, I'm Jimmy Chang. I've been teaching college math for nine years, and when you see a sentence, no equations to speak of, and it's your job to write the equation that can feel a a little intimidating sometimes, but I'm here to give you a couple of of tools on how to break down the sentence as much as possible, and that'll allow you to write an equation that the words are talkin' about. So, here we go. The first example that we'll be lookin' at is the sentence four less than a number is twelve. Now, at first those words sound very intimidating, but here's a couple of tips for you. Always break it up into as many little pieces as possible. Now, four less than; let's take a look at those three words. Now, you know the number four is going to be involved because' it's four less than, but if you have a number four less than that indicates always subtraction, so that means it's going to be a minus four, okay? Now, what about more than? We'll talk about that later, but for right now four less than means minus four. Now, a number; now, we don't know what this number actually is, so let's just call it n, n for number. Now, the is; the is is always, guaranteed always going to be the word for equal sign, so equal to and then you have twelve. The number after the is is always going to be the number on the other side, and as you can tell this equation is a very easy one to solve. Now, here's another example for you. Three more than twice a number is eighteen. Now, we did less than up there a minute ago. Now, three more than; now, if a number less than means subtraction then three more than would mean addition, so there's going to be a plus three. That's what the three more than represents. Now, twice a number; now, if you're doing something twice you're doing it two times. Did I just say two times? Well, that's exactly what you're supposed to do. Twice a number means two times a number, so you have two n, two times n. Is, we now know is equal, and then eighteen which is over there. Again, that's a very easy equa equation to solve, but once you have words you'll be able to, as long as you know what they mean you'll be able to solve an equation and set it up very quickly. So, I'm Jimmy Chang, and that is how you write an equation.