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Current time:0:00Total duration:3:34

Video transcript

so I have six different expressions here and what I want you to do is pause this video and try to calculate the value of each of these expressions I'm assuming you've given a go at it now let's work through them so when we see something like this we have to remember our order of operations we have two times three squared and we have to remember that the first thing we need to think about are the parentheses parentheses I'll just write paren for short then we worry about exponents exponents exponents then we will worry about multiplication and division and actually let me write it this way we worry about multiplication and division and then we worry about addition and subtraction so in this expression right over here there are no parentheses so we do the exponents first so we calculate what 3 squared is 3 times 3 is 9 so this becomes 2 times 9 which is equal to 18 now let's look at this one this one is interesting because we they have its it looks like the same expression but now there are parentheses and because of these parentheses we were going we're going to do the multiplication before we take the exponent so 2 times 3 is going to be 6 and we're going to take that to the second power so that's 6 times 6 which is equal to 36 now let's think about this one right over here once again we want to do our multiplication in our division first so we have a division right over here 81 over 9 is the same thing as 81 divided by 9 that's going to be 9 and then we have subt becomes 1 plus 5 times 9 now we want to do the multiplication before we do the addition so we're going to do our 5 times 9 which is 45 so this becomes 1 plus 45 which of course is equal to 46 now let's tackle this one right over here so we would want to do the exponents first so 1 squared well that's just going let me do this in a different color 1 squared is just going to be equal to one so that's just going to be equal to one and so you have two times four plus one what should you do should you add first or do the multiplication first well multiplication takes precedence over addition so you're going to do the two times four first two times four is eight so you're going to have eight plus one which of course is equal to nine now you have a very similar expression but you have parentheses so that's going to force you to do what's in the parentheses before you take the exponent but within the parentheses we have multiplication in addition now we have to remember that we do the multiplication first so we're going to do the two times four first so that's going to be eight plus one plus one to the second power eight plus one is nine so that's nine to the second power nine squared not or is the same thing as nine times nine which is equal to 81 now we have one more right over here that looked very similar to this one except once again we have parentheses that's making us do the addition first without parentheses we would do the multiplication in the division first but here we see that 1 plus 5 is 6 and then we have this 81 over 9 which is 9 so this simplifies to 6 times 9 which of course is equal to 54