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Current time:0:00Total duration:1:21

Understanding square roots

CCSS.Math:

Video transcript

we're asked to find the square root of 100 let me write this down bigger so the square root is this big check looking thing the square root of a hundred and when you see it like this this means the positive square root if you're familiar with negative numbers you know that there's also a negative square root but when you just see this symbol that means the positive square root so let's think about what this is saying this is asking us find the number the positive number that when I multiply by when I multiply that number by itself I get 100 so what number when I multiply by itself do I get a hundred let's see if I multiply 9 by itself that's only going to be 81 if I multiply 10 by itself that is a hundred so this is equal to and let me write it this way normally you could skip the step but you could write this as the square root of and instead of 100 100 is the same thing as 10 times 10 and then you know the square root of something times itself that's just going to be that's something this is just equal to 10 so the square root of 100 is 10 or another way you could write I guess the same truth is that 10 squared which is equal to 10 times 10 is equal to 100