If we take a look at a question like this one, there's a lot of stuff going on. There's an addition, some brackets, division, an index or order, and a multiplication. We call each of these things an operation, and we have to do them all in a specific order. We can't just start on the left and work our way through.
To help us remember this order, we can use something called BODMAS or BIDMAS, which are both exactly the same except for this second letter, which can be an O or an I, depending on which one you've learned. Each letter stands for a different operation and the order of the letters tells us the order in which we should do the operations. So first we should always look at Then we should look at the order or index, which is the little raised number when you square or cube something and is often called the power.
Then any division, multiplication, addition, and finally subtraction. One important thing though is that when it comes to division and multiplication or addition and subtraction, you should start with the ones on the left. and work your way to the right.
So if you have a question like this one with loads of plus and minuses you would just start on the left and work your way through to the right. You wouldn't have to do all of the additions before the subtractions. Getting back to our example though, the first thing that we would do is look at the brackets and as the only operation inside the brackets is a divide we do that straight away. So 18 divided by 6, which equals 3. And now that the 3 is the only thing inside the brackets, we can just get rid of the brackets. And our equation is now 3 plus 3 squared times 2. The next thing on our list is the order, or index, which is this power of 2. This means that we have to do 3 times by itself.
so 3 times 3 which equals 9. So we now have 3 plus 9 times 2. Next up is division but there isn't any division in our equation so we can skip that and go on to multiplication which we do have as 9 times 2 which is 18 leaving us with 3 plus 18 and now the only thing left is this addition. So we do 3 plus 18 to get 21 as our final answer. Let's try one more.
So first of all we need to look for any brackets and this time there are two sets of brackets so we'll have to look at one of them and then the other one. It's completely up to you which one you want to do first but in general I would say it's just easier to start on the left and then work to the right. So we'll start with this one on the left.
Now notice that we haven't highlighted this order of two up here. That's because the order is outside of the bracket, so we don't consider it yet. We're only focusing on what's inside the bracket for now.
Within the bracket, the first thing we have to do is the order of two on the four. So 4 squared, which is 16, giving us 16 minus 6 times 2 inside the bracket. There isn't any division in the bracket.
So the next thing we do is the multiplication. 6 times 2, which is 12. And then the only thing left is the subtraction. So 16 minus 12, which gives us 4. At this point we've finished simplifying this first bracket so we can rewrite our equation as 4 squared divided by the bracket 4 divided by 2 times 4 plus 7. And then next we're going to have to deal with this other bracket and the only operations inside it are a division and a multiplication. So we do the division first 4 divided by 2 which is 2 and then we can multiply that 2 by the 4 to get 8. So now we have 4 squared divided by 8 plus 7. Now that we've got rid of all the brackets, the next thing to do is this order on the 4. So 4 squared which is 16. Next we do the division.
So 16 divided by 8 which is 2. And finally the addition, so 2 plus 7, which gives us 9 as our final answer. And that's it. That's everything that you need to know about BodMass. If I could give you one tip, I'd say the hardest thing with this topic is just remembering to use it.
So whenever you do an equation, just think of BodMass and think, which of these operations should I do first? Because most people just completely forget to use it. and that's where they make all their mistakes. Anyway, I hope you enjoyed the video and found it useful in some way. If you did, then please do share it with your friends and hopefully we'll see you again soon.