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Current time:0:00Total duration:3:49

Video transcript

let's see if we can write 21 sixtieths as a decimal and I'll give you a little hint see if you can rewrite this as a fraction with a hundred as the denominator or another way to see 8 another way to say see if you can rewrite this so it's a certain number of hundredths and then you can represent that as a decimal so we've done this before we can rewrite a fraction we can get an equivalent fraction if we either multiply the numerator and the denominator by the same quantity or we divide the numerator and the denominator by the same quantity and this numerator and this denominator it looks pretty clear 21 is divisible by 3 and 7 + 1 + 21 + 60 is clearly divisible by 3 as well it's not divisible by 7 or 21 well of course it's divisible by 1 but that doesn't really help you much so let's see if we can rewrite this maybe with lower numbers where we divide both the numerator and the denominator by that common factor of 3 so we're dividing by 3 so I'm just rewriting this as an equivalent fraction that might make it a little bit easier for our heads to get around it so 21 divided by 3 is equal to 7 and 60 divided by 3 is equal to 20 so we've rewritten 21 sixtieths as 7 xx so you might be saying Sal why did you even do this did aren't we trying to get it in terms of hundredths well this was kind of a this one helps simplify it in my brain a little bit and what's extra good about writing it is 720 it's is that it's much it's easy to go from 20 to 100 to go from 20 to 100 we just have to multiply by 5 well if each section is going to be 5 times as many then these 7 sections are going to be five times as many so once again we're multiplying the numerator and the denominator by the same thing and so this is going to be equal to 35 over 100 or 35 hundredths 35 we write it a little bit 35 hundredths which is what we wanted to do we wanted to rewrite this in terms of hundredths and what is 35 hundredths well let's just remind ourselves when we're writing a decimal that's the ones place that's the ones place this right over here this next place is the tenths place that's the tenths place and the next place is the hundreds place is the hundreds hundreds place and so 35 hundredths well you could write that like this you could write that as 35 hundredths so you could literally write this as 0.35 and you might say wait wait you put a three in the tens place why is this 35 hundreds I get that this is five hundreds but why is this 35 hundredths well three tenths is 30 hundredths so this is thirty-five hundred so another way of thinking about it you could rewrite this right over here you could rewrite this as being equal to 30 30 over 100 30 over 100 plus five over 100 plus five over 100 and well how can and what is 30 over 100 if you wanted to rewrite it in terms of tenths well you could just divide the numerator and the denominator by 10 divided by 10 and you would get three tenths three tenths plus 5/100 plus 5/100 and we see that right over here three tenths that's the tens place plus 5/100 so that's the hundreds place or this is sometimes referred to as 35 hundredths 35 hundredths