Get Pupils Solving Equations With Bar Models

Hi, I'm Felicity, and today we're going to be looking at how we can use bar models to solve algebraic equations. Now, whilst bar models don't solve these equations on their own, they're a really important tool for helping students visualize what's otherwise a totally abstract concept. So let's take this example. I've got four A plus seven, which equals 27. And we want to figure out the value of A, which is an unknown value at the moment. So if we take our bar model, we know that the total value is 27, so I've labeled that up here. I know one part is a value of seven and then there are remaining four equal parts, all of which are the value of A. We want to figure this out so we can use our known values 27 and 7 to help figure out the value of A. So 27, subtract 7 gives us 20. Now, this gives us the value of these four parts altogether. So 4A equals 20, but we want to figure out the value of A on its own. So I simply need to divide 20 by 4, which gives us 5. So we now know that A equals 5. And finally, it's a really good idea to get students to just plug this new value back into the original equation, just to check that it actually works. So I've got four times five plus seven, which we know equals 27. And that's how you can use bar modelling to solve algebraic equations.