Videos

Math 7 - Module 2B - Lesson 13 Day 1 - Exercise 2

Added Apr 25, 2021 •

Copy this URL:
Embed code:	<iframe class="edlio-embed-player" type="text/html" width="640" height="360" src="//www.oakmil.org/apps/embed/?v=316292" frameborder="0" allowfullscreen></iframe> Change dimensions

Convert a Fraction to a Decimal

Show Transcript

so 3/16 that's not converting each fraction to a decimal using an equivalent fraction look at this right here 3 / 16 what can we do all right someone said let's do the one on the bottom for all right let's do the one on the bottom so convert needs one thing we can do look at that that's an improper fraction we can make you can make this a 10 we can make this a 10 but let's make it a mixed number first how many fives are in 7 there's one set of 5 so that's take out 5/5 you have a 1 hair let me rewrite it let's go 5/5 + 2/5 5/5 + toothpaste make 7/5 that's another way of writing 1 + 2/5 which is 1 + 2/5 Amazon the right here change the 2/5 into something over 10 better than most smallest possible so what just look at the fraction so put a, we're done with the one we'll put that back got a whole number 2/5 so how do we make it into something over 10 is that number sense cuz 5 can become 10 you don't have to make 100 good times two * 2/2 + 5 * 2 is 10 two times two is four so we have one and four tenths what do the whole number last over 10 we know our answers going to have one decimal place so just fill in the numerator in the decimal place 0.4 but we have this phone number in front so technically that's a OnePlus 2/5 and the 2/5 Is 4/10 which is a point worth 1 + 2.4 so don't forget your whole number one plus 0.4 that equals 1.4 it is let's go into the last one notice what I'm doing I saw that I had a v i can easily change at the something over 10 I saw that is 1616 times what could become something over 10 I don't know over a hundred 32 can I make that over something over with zeros tens hundreds I don't know but look at this next one over 50 I can easily do that and this is what you guys this is testing strategy right here big eyes during test do one problem after the other you spend too much time doing one when you could have did the next one which is way easier always do the ones you could do first then go back so I'm going to go do this one first 35 / 100 I'm using Tesla Model what's different about it there different fractions but this was improper where is this is proper I don't need to do anything sure I can simplify it but I'm not going to waste time because this I can multiple there's two ways I'll do it twice so somebody up here says / 5 someone said * 2 I'll do both what's * 2 first 35 * 2 50 * 2 * value of 1 50 * 2 made a fraction over 100 so we know it's going to be two decimal places so 0.8 Akron OH two decimal places whatever that number is that wasn't the decimal place 35 * 2 70 but notice zeros after in the back are placeholders we learned about that earlier point seven for some reason we like doing multiplication that's why we would did division last lesson learn to divide if we could divide watch this 35 + 50 both share a five that we can divide out / 5 / 5 5 / 5 is a one we just change the value we don't change the valley would you change 35 / 5 is 750 / 5 is 1007 / 10 / 10 add a zero there that's one decimal place so is zero point some X and all we do is put the numerator in the decimal place 0.7 look at this same thing which way was better I don't know they're both the same to me most people will say the green only cuz it's less work less writing but it's not that much writing I'll say this the multiplication is easier cuz a lot of guys are more comforter with multiple k even though it's a little bit more rainy the green is only easier cuz it's less writing but it's not that much but then that involves division with a lot of guys get stuck on start the practice to see the multiplication and division the same thing just you're looking at it differently all right if this was a test and you got all this you got half a credit 50 points so far 50% you're so much you do some work on this you'll get even more you're so much closer together see and that's what me off about you guys when you guys do a test there were some ones that are super easy but you spend so much time in the first one you freaked out and gave up testing strategies always do the ones that you can do first you don't have to go in I'm scared Russ lyrics * 5 / 5 3 * 5 is easy it's 15 160 * 5 that is what 80 80 it doesn't quite get us to over 100 or over 10 but notice it ends in a zero now we can do something there is it going to be nice who knows so we can figure out what we want to do to win over a thousand over ten semi-final let's go 101st how does Aiden come and hunt I can't do that we can make it in the 10 siletz / 8 yep so let's make it so now it's make it over 10:15 / 8 SI the remainder or some destiny but at the very least 80 / eight becomes 10 and when you get this messed up thing 15 / 8 ready by 10 that's not fun to do but it's alright 15 / 8 it is what it is let's go look at that he decided to do they meaning so do this right here so they went over three times sick they went they use exponents we don't use exponents that's what they decide to do so 16 times what gets us to some number so we got to find some 3 / 16 16 times what number sum same number equals and here's the thing we know it can't equal 10 unless we divide so we're not going to bother with that 16/16 times something equal 100 100 I don't know either I just made it as it's old and it's question I'm asking is 16 times something equals 1000 no can 16 times something equal 10000 I don't know tell you yes 5 so what do I multiply to 16 to get 10,000 and that's the hard part 2 distraction right now that's why I'm going to show a different method next lesson but for now it's practice 1001 so it's * 16 * 5 was 80 * 5 gets us 400 * 5 gets us 2000 + x 5 gets us 10000 cenotes real look what I did it's always going to be some type of thing to get us zeros at the end 16 * 5 goddess 8080 X 540 no one in front cuz they always want some what's a multiple of just straight-up 10 a factor and exponent of 10 80 * 5 is 400 400 * 5 is 2000 mm * 5 now we got to one so what is it as 5 * 5 * 5 * 5 multiplication that's exponents 3 * 16 * 5 ^ 4 Sun teaching you guys something new which this thing expected you guys to know what are exponents and exponent is a short way of writing repeated multiplication 15253 545 and what are we doing with each by 4 * 205 * 5 * 5 * 5 I'm already tired of the short way is writing it as an exponent this is how many time we have five and how many times I multiply so right there what's 5 * 5 * 5 is 2525 * 5 is 125 and 125 time 5 what is 125 * 5 when the 501 2625 so we're multiplying 3 by 625 so this is 3 * 6 3 * 6 notice all the stuff my work notice how I got everything lined up right here that's clean and everything that I couldn't do in my mental math I do it off to the side Oso Murray 625 whatever that is 3 is 1875 so all right let's change it to a decimal so to change it over to decimal how many zeros we have one two three four so we know all we got four decimal places to plug that number in here starting with the back if we have the same amount of numbers as faces just put it in if we have left numbers that there are spaces you always want to fill it in from the back and then put a zero placeholder there if there's a we don't have extra space 0.1875 but if we read it correctly read it without the desolate 1875 10,000 little bit more work to go from fraction the decimal all right see is very similar so that was a right there I know I know putting it over at so someone said so that's all that we learn one message we're going to learn another method should we go to lesson 14 cuz I know by the time you finish the rest and come back to this lesson most of you guys will have forgotten what we have to do so we do a quick review that's all right so that we're going to a bunch of different problems that's what that class will be when we come back all right so let's go look at see this is BFA right here she is the same thing he is very much the same thing all right let's look at this so go I don't have enough space to do work there 11 / 32 so 11/32 let's multiply by fives and see what happens cuz 32 * 5 what is that a 10 and then 151 + 160 that doesn't donate time spy that's a zero 30 carat 800 doesn't do anything for us there so that's 152 what time does another five fast for 1000 * 5 20000 X another 5 100000 so it takes us 1 2 3 4 5 V ^ 5 so to get to something with a bunch of zeros in a one in the front so times what did I say one two three four by the power of 5 so it's 11 * 5 ^ 5 I don't know what that is but let's stop and this is a thing about math in our last problem weed 5 ^ 4 V ^ 4 was a 625 625 that's 5 ^ 4 that means If I multiply to another 5 to it it would have been fine if I just take this to the power of 5 that's why you never want to cross on throw your work to sometimes in another problem you're going to use your work again so all we do is put in another multiple of 5 5 * 5 is 25 * 20 is 105 * 603000 3125 and we multiply what's 5 ^ 5 to 11 cuz we know that 32 times that is 100000 CI to look at us and then you already did all right I got to show it to everybody else though let's go 11 times what did I say it was 2225 * 11 * 3125 + 0 50125 733-430-4375 all right now here's the thing we got this far it seems like a lot of all we're done we're not the problem wanted this become a decimal remember to write down two decimal places zero point unless we have a whole number how many zeros are there 1 2 3 4 buy one two three four five we know that's how many decimal places so fit that into here five numbers 5 decimal places someone asked so I'm going to go back now this will be a question I'm going to give you guys I'm going to make this up we're going to practice this next class become somebody else what happens if we have more small space has been the numbers of the number I'm making it up right now I'm going to go 46 / alright 46 / 10000 no it's going to be zero point and we got four decimal spots 1234 if you have more decimal places the numbers you always start in the back I got two numbers so you put it in the bag zero-point XX 46 and all the exes get replaced with zero placeholders that's all it is all right so the Nets made that was homework exercise he was homework we're going to go over we need more practice if you want to try and do it the problem set right here this is your next homework so I'm splitting it up do not turn

Uploaded by W. Leung.

Videos

Math 7 - Module 2B - Lesson 13 Day 1 - Exercise 2

More videos from W. Leung