1 00:00:00,000 --> 00:00:00,550 2 00:00:00,550 --> 00:00:06,870 We're asked to write 7/8 as a decimal and as a percent. 3 00:00:06,870 --> 00:00:08,620 We'll start off with a decimal, and we'll see it's 4 00:00:08,620 --> 00:00:12,260 pretty easy to go from a decimal to a percent. 5 00:00:12,260 --> 00:00:14,660 Now, whenever you see a problem like this, it's 6 00:00:14,660 --> 00:00:15,510 sometimes confusing. 7 00:00:15,510 --> 00:00:18,000 It's like, how do I even get it into a decimal, or as a 8 00:00:18,000 --> 00:00:20,380 fraction over 100, or as a percentage? 9 00:00:20,380 --> 00:00:24,160 And you always have to remember 7 over 8, or 7/8, is 10 00:00:24,160 --> 00:00:25,490 the exact same thing. 11 00:00:25,490 --> 00:00:28,120 12 00:00:28,120 --> 00:00:33,090 This means literally 7 divided by 8. 13 00:00:33,090 --> 00:00:34,830 Not 8 divided by 7. 14 00:00:34,830 --> 00:00:37,180 7 divided by 8. 15 00:00:37,180 --> 00:00:40,580 The numerator divided by the denominator. 16 00:00:40,580 --> 00:00:42,260 And you say, well, how do I turn that into a decimal? 17 00:00:42,260 --> 00:00:45,010 Well, we just literally do a long division problem, but we 18 00:00:45,010 --> 00:00:48,410 keep going behind the decimal point, so that we don't end up 19 00:00:48,410 --> 00:00:50,860 with a remainder, or until we end up with things repeating. 20 00:00:50,860 --> 00:00:51,540 You'll see what we mean. 21 00:00:51,540 --> 00:00:54,330 In this case, we won't end up with anything repeating. 22 00:00:54,330 --> 00:00:55,790 So let's try this out. 23 00:00:55,790 --> 00:00:57,555 So it's 7 divided by 8. 24 00:00:57,555 --> 00:01:03,070 25 00:01:03,070 --> 00:01:06,910 So how many times does 8 go into 7? 26 00:01:06,910 --> 00:01:08,530 Well, 8 does not go into 7. 27 00:01:08,530 --> 00:01:10,250 It goes zero times. 28 00:01:10,250 --> 00:01:12,180 And actually, just so that we make sure that everything's 29 00:01:12,180 --> 00:01:14,280 clean, let's put our decimal. 30 00:01:14,280 --> 00:01:19,020 You can view this as 8 going into 7.000. 31 00:01:19,020 --> 00:01:21,940 You can keep adding as many zeroes as you need until 32 00:01:21,940 --> 00:01:23,130 you're done dividing. 33 00:01:23,130 --> 00:01:26,970 So we have our decimal point right here, right behind the 7 34 00:01:26,970 --> 00:01:27,640 where it was up here. 35 00:01:27,640 --> 00:01:30,230 So we say 8 goes into 7 zero times. 36 00:01:30,230 --> 00:01:33,090 0 times 8 is 0. 37 00:01:33,090 --> 00:01:34,410 You subtract. 38 00:01:34,410 --> 00:01:36,520 7 minus 0 is 7. 39 00:01:36,520 --> 00:01:38,980 Now we can bring down a 0. 40 00:01:38,980 --> 00:01:40,230 We bring down a 0. 41 00:01:40,230 --> 00:01:41,570 It becomes 70. 42 00:01:41,570 --> 00:01:45,010 And then you say 8 goes into 70 how many times? 43 00:01:45,010 --> 00:01:47,370 Well, 8 times 8 is 64, so that works. 44 00:01:47,370 --> 00:01:48,950 8 times 9 is 72. 45 00:01:48,950 --> 00:01:49,980 That's too big. 46 00:01:49,980 --> 00:01:51,230 So it goes into it eight times. 47 00:01:51,230 --> 00:01:54,730 48 00:01:54,730 --> 00:01:57,250 8 times 8 is 64. 49 00:01:57,250 --> 00:02:03,060 When you subtract, 70 minus 64 is 6. 50 00:02:03,060 --> 00:02:05,080 You still have a remainder, so let's keep going. 51 00:02:05,080 --> 00:02:07,260 Let's bring down another 0. 52 00:02:07,260 --> 00:02:11,580 So you bring down another 0 right over there, and so you 53 00:02:11,580 --> 00:02:13,520 say, how many times does 8 go into 60? 54 00:02:13,520 --> 00:02:16,480 8 times 8 is 64, so that's too big. 55 00:02:16,480 --> 00:02:20,670 8 times 7 is 56, so that'll work. 56 00:02:20,670 --> 00:02:24,680 So it goes into 60 seven times. 57 00:02:24,680 --> 00:02:27,800 7 times 8 is 56. 58 00:02:27,800 --> 00:02:29,010 You subtract. 59 00:02:29,010 --> 00:02:32,300 60 minus 56 is 4. 60 00:02:32,300 --> 00:02:34,780 So we still have a remainder, so let's keep bringing down 61 00:02:34,780 --> 00:02:35,970 some zeroes. 62 00:02:35,970 --> 00:02:39,210 So let's bring this 0 down here. 63 00:02:39,210 --> 00:02:41,710 And 8 goes into 40 how many times? 64 00:02:41,710 --> 00:02:45,690 Well, 8 times 5 is 40, so it goes in nice and evenly. 65 00:02:45,690 --> 00:02:47,400 So it goes into it five times. 66 00:02:47,400 --> 00:02:50,880 5 times 8 is 40. 67 00:02:50,880 --> 00:02:51,890 Subtract. 68 00:02:51,890 --> 00:02:53,200 No remainder. 69 00:02:53,200 --> 00:02:56,450 So as a decimal, we just figured out that 7/8, which is 70 00:02:56,450 --> 00:03:04,820 equal to 7 divided by 8, is exactly 0.875. 71 00:03:04,820 --> 00:03:11,390 So 7/8 as a decimal is equal to 0.875. 72 00:03:11,390 --> 00:03:13,490 Now we've done the decimal part. 73 00:03:13,490 --> 00:03:15,200 Now the next thing is to do a percent. 74 00:03:15,200 --> 00:03:17,520 And if you have it as a decimal, doing it as a percent 75 00:03:17,520 --> 00:03:19,160 is very easy. 76 00:03:19,160 --> 00:03:22,440 You literally shift the decimal place two to the 77 00:03:22,440 --> 00:03:24,280 right, and you put a percent sign there. 78 00:03:24,280 --> 00:03:25,930 And I think it makes sense why it works. 79 00:03:25,930 --> 00:03:28,520 Now you're going to say, how many per hundred? 80 00:03:28,520 --> 00:03:33,600 You can view this as 875 thousandths. 81 00:03:33,600 --> 00:03:34,430 Let me write this down. 82 00:03:34,430 --> 00:03:35,800 You can view this as a fraction. 83 00:03:35,800 --> 00:03:41,050 You could say, well, this is the same thing as 875/1,000. 84 00:03:41,050 --> 00:03:42,620 That's how we've read it in the past. This is the 85 00:03:42,620 --> 00:03:45,950 thousandths spot right here. 86 00:03:45,950 --> 00:03:53,340 Or you could read this as 87.5/100. 87 00:03:53,340 --> 00:03:56,570 If you just go two decimal places, it's 87.5/100. 88 00:03:56,570 --> 00:03:59,060 Or if you just took this, and you divide the numerator and 89 00:03:59,060 --> 00:04:01,170 the denominator by 10, you would get this. 90 00:04:01,170 --> 00:04:06,700 And this is literally saying 87.5 per 100, So this second 91 00:04:06,700 --> 00:04:12,195 statement right here, this is literally saying 87.5 per 92 00:04:12,195 --> 00:04:15,560 hundred, or per cent. 93 00:04:15,560 --> 00:04:21,440 So this is equal to 87.5%. 94 00:04:21,440 --> 00:04:23,560 So that gives you the reasoning for why it works, 95 00:04:23,560 --> 00:04:26,300 but the really easy way, if you have a decimal, to make it 96 00:04:26,300 --> 00:04:30,710 into a percent, you literally multiply the number by 100 and 97 00:04:30,710 --> 00:04:32,820 put the percent there, which is essentially telling you 98 00:04:32,820 --> 00:04:35,090 that you're going to divide by 100, so you're multiplying and 99 00:04:35,090 --> 00:04:36,040 dividing by 100. 100 00:04:36,040 --> 00:04:39,460 So if you multiply this by 100, which is equivalent to 101 00:04:39,460 --> 00:04:42,520 shifting the decimal place two places to the right, that 102 00:04:42,520 --> 00:04:47,570 literally would become 87.5, then you 103 00:04:47,570 --> 00:04:48,630 want to put the percent. 104 00:04:48,630 --> 00:04:51,310 This says this is going to be over 100. 105 00:04:51,310 --> 00:04:53,360 So you multiply by 100, and then divide by 100. 106 00:04:53,360 --> 00:04:55,510 You're not really changing the number. 107 00:04:55,510 --> 00:04:57,010 Hopefully, that makes sense. 108 00:04:57,010 --> 00:04:58,820 Another way to remember, because sometimes you might 109 00:04:58,820 --> 00:05:02,280 get confused-- Do I put the decimal to the right? 110 00:05:02,280 --> 00:05:04,550 Do I take it to the left-- is that the decimal 111 00:05:04,550 --> 00:05:07,890 representation will always be smaller than the percent 112 00:05:07,890 --> 00:05:08,940 representation. 113 00:05:08,940 --> 00:05:10,820 And not only will it be smaller, but it will be 114 00:05:10,820 --> 00:05:15,060 smaller by exactly a factor of 100. 115 00:05:15,060 --> 00:05:17,870 This is 100 times smaller of a number right here 116 00:05:17,870 --> 00:05:19,910 than just the 87.5. 117 00:05:19,910 --> 00:05:21,980 Obviously, when you put this percent here, these become the 118 00:05:21,980 --> 00:05:24,390 exact same number. 119 00:05:24,390 --> 00:05:24,599