About this video
The video finds expressions equal to 2% of 90. It rewrites 2% as 2/100, 1/50 and 0.02, so 2% of 90 equals 2/100 x 90, 1/50 x 90 or 0.02 x 90. It then rules out 0.2 x 90 (that is 20%), 200 x 90 and 2 x 90.
You'll be able to
- write a percent as a fraction over 100, a simplified fraction and a decimal.
- pick expressions that equal a percent of a number.
- explain why 0.2, 2 and 200 are not the same as 2%.
Key words
- percent
- Per 100; 2% means 2 per 100.
- hundredths
- Parts of a whole cut into 100 equal pieces; 0.02 is two hundredths.
- equivalent
- Having the same value, even if written differently.
Transcript
- [Instructor] We're asked which of the following options have the same value as 2% of 90? Pause this video, and see if you can figure it out. And as a reminder, they say, pick two answers. All right, now let's work through this together. So before I even look at the choices, I'm just going to try to think of all of the ways that I can write 2% of 90.
2%, this right over here, this literally means two per 100. So I could view it as the same thing as two over 100, times 90, that's one way to write 2% of 90. Two over a 100, I can divide both the numerator and the denominator by two. And so two over a 100 is also the same thing as one over 50.
And so it could also be one over 50, times 90. Now let's see what other choices they have here. Well, I could also write 2% as a decimal. Two-hundredths should be written like this. Zero point, this is the tenths place. I have no tenths, but I have two-hundredths.
So I'm multiplying that by 90. All of these right over here are equivalent to the 2%, 2% of 90. All right, now let's look at the choices. This is 0.2 times 90. This is not 2%. This actually would be two-tenths, or 20%. So let me rule that one out. This one right over here.
This is two-hundredths times 90. We already wrote that down. I like this choice. 200 times 90. No, that would be far larger than what we are looking for. We are looking for two-hundredths, not two hundreds times 90, so definitely rule that one out. Two times 90.
Well, no, we're looking for 2% of 90, not two times 90. Once again, this is too large. And then we have two-hundredths times 90, which is the first thing that we wrote. And so I like this choice as well.
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