1 00:00:00,000 --> 00:00:08,180 How did the U.S. Standard System of Measurement develop? 2 00:00:08,180 --> 00:00:10,400 How is the metric system devised? 3 00:00:10,400 --> 00:00:13,120 How are the two systems different? 4 00:00:13,120 --> 00:00:17,120 Let's begin our measurement journey by visiting the Peninsula Fine Arts Center in Newport 5 00:00:17,120 --> 00:00:18,880 News, Virginia. 6 00:00:18,880 --> 00:00:21,880 People have been measuring things for thousands of years. 7 00:00:21,880 --> 00:00:25,280 Hey, that's one thing we measure, time. 8 00:00:25,280 --> 00:00:27,560 What are some of the other things we measure? 9 00:00:27,560 --> 00:00:28,560 Temperature. 10 00:00:28,560 --> 00:00:29,560 How high is it? 11 00:00:29,560 --> 00:00:30,560 Volume. 12 00:00:30,560 --> 00:00:31,560 How much space is in your garage? 13 00:00:31,560 --> 00:00:32,560 Mass and weight. 14 00:00:32,560 --> 00:00:33,560 How heavy is it? 15 00:00:33,560 --> 00:00:34,560 Length. 16 00:00:34,560 --> 00:00:42,280 How long is your street? 17 00:00:42,280 --> 00:00:43,280 Get this. 18 00:00:43,280 --> 00:00:47,720 The ancient Egyptians used their fingers, hands, and even arms to measure things. 19 00:00:47,720 --> 00:00:50,120 There were no measuring tools like rulers back then. 20 00:00:50,120 --> 00:00:54,880 The width of one finger was a digit, and the width of four fingers was a palm. 21 00:00:54,880 --> 00:00:57,640 Here's another ancient Egyptian measurement. 22 00:00:57,640 --> 00:00:59,840 Open your hand and spread out your fingers just like this. 23 00:00:59,840 --> 00:01:04,680 The distance from the tip of your thumb to the end of your little pinky was called a 24 00:01:04,680 --> 00:01:05,960 span. 25 00:01:05,960 --> 00:01:09,560 The ancient Egyptians also created a measurement called the cubit. 26 00:01:09,560 --> 00:01:13,400 If you bend your arm, the distance from the elbow to the tip of your middle finger was 27 00:01:13,400 --> 00:01:14,400 a cubit. 28 00:01:14,400 --> 00:01:18,400 In the ancient world, the cubit was the most popular way to measure length. 29 00:01:18,400 --> 00:01:22,560 So you see, all these units of measurement were based on something familiar to ancient 30 00:01:22,560 --> 00:01:24,920 people, body parts. 31 00:01:24,920 --> 00:01:30,080 Of course, using your hand or elbow to measure a pyramid would take forever. 32 00:01:30,080 --> 00:01:33,480 Not only that, it's not an accurate or exact measurement. 33 00:01:33,480 --> 00:01:34,920 Here's why. 34 00:01:34,920 --> 00:01:36,680 My friend Jimmy is taller than I am. 35 00:01:36,680 --> 00:01:40,680 It takes four of my cubit arm lengths, but only three of his to measure my butt. 36 00:01:40,680 --> 00:01:44,200 How can we get the same measurement if our arms are different lengths? 37 00:01:44,200 --> 00:01:45,200 Good point. 38 00:01:45,200 --> 00:01:49,160 In ancient Egypt, it was up to the pharaoh to decide how to make measurements standard, 39 00:01:49,160 --> 00:01:52,160 or the same, for all situations. 40 00:01:52,160 --> 00:01:56,620 So the standard cubit length was set by the length of the pharaoh's arm. 41 00:01:56,620 --> 00:02:01,480 But even then, it could be pretty tough measuring a pyramid with a pharaoh under your arm. 42 00:02:01,480 --> 00:02:04,480 As time went on, people created many ways to measure things. 43 00:02:04,480 --> 00:02:07,920 Unfortunately, none of them were the same when it came to mathematics. 44 00:02:07,920 --> 00:02:12,840 You see, scientists couldn't repeat each other's experiments because there was not an agreed-upon 45 00:02:12,840 --> 00:02:14,240 standard of measurement. 46 00:02:14,240 --> 00:02:18,040 Today, our world operates according to two different systems of measurement. 47 00:02:18,040 --> 00:02:20,880 Here's some expert help. 48 00:02:20,880 --> 00:02:27,320 In the U.S. standard system, the inch, foot, yard, and mile develop from traditional practices 49 00:02:27,320 --> 00:02:30,920 of measurement dating back to ancient times. 50 00:02:30,920 --> 00:02:36,040 One disadvantage of the U.S. standard system is the different size units often have no 51 00:02:36,040 --> 00:02:38,240 simple relationship to each other. 52 00:02:38,240 --> 00:02:51,120 For instance, there are 12 inches in a foot, 3 feet in a yard, 1,760 yards, or 5,280 feet 53 00:02:51,120 --> 00:02:53,000 in a mile. 54 00:02:53,000 --> 00:02:57,760 Converting different units of measurement, like miles to inches, requires some math. 55 00:02:57,760 --> 00:02:59,320 Here's an example. 56 00:02:59,320 --> 00:03:03,840 It's about 431 miles from Los Angeles to San Francisco. 57 00:03:03,840 --> 00:03:09,360 To convert these miles into inches, simply multiply the number of miles, 431, by the 58 00:03:09,360 --> 00:03:16,200 number of feet in a mile, 5,280, by the number of inches in a foot, 12. 59 00:03:16,200 --> 00:03:22,240 431 miles converts to 27,308,169 inches. 60 00:03:22,240 --> 00:03:23,240 Whew! 61 00:03:23,240 --> 00:03:30,200 Using the decimal system is a much easier way to measure and change units. 62 00:03:30,200 --> 00:03:35,040 Because earlier systems of measuring units were so confusing, the decimal system was 63 00:03:35,040 --> 00:03:36,560 devised. 64 00:03:36,560 --> 00:03:41,000 This system is based on tens and multiples of tens. 65 00:03:41,000 --> 00:03:47,000 Tenth numbers, or decimals, are easier to use than the U.S. standard system, which is 66 00:03:47,000 --> 00:03:49,360 based on twelfths. 67 00:03:49,360 --> 00:03:53,840 One advantage of the decimal system is the decimal point. 68 00:03:53,840 --> 00:04:00,920 Depending upon where it is moved, whole numbers can become fractions or multiples of tens. 69 00:04:00,920 --> 00:04:03,040 Thanks, Dr. Morgan. 70 00:04:03,040 --> 00:04:05,720 We now know why there is a metric system of measurement. 71 00:04:05,720 --> 00:04:09,240 Yep, and the metric system is based on the meter. 72 00:04:09,240 --> 00:04:13,520 The original meter was not the length of someone's finger or arm. 73 00:04:13,520 --> 00:04:18,280 Instead, it represented one ten-millionth of the distance from the North Pole to the 74 00:04:18,280 --> 00:04:19,280 equator. 75 00:04:19,280 --> 00:04:25,200 Hey, the meter is the most widely used measurement system for scientific work. 76 00:04:25,200 --> 00:04:29,160 Using the metric system, we can easily convert units with some mental math. 77 00:04:29,160 --> 00:04:35,800 For example, we know Los Angeles is approximately 600 kilometers from San Francisco. 78 00:04:35,800 --> 00:04:39,960 Now if we want to know that same distance in meters, for example, all we have to do 79 00:04:39,960 --> 00:04:42,560 is multiply by 1,000. 80 00:04:42,560 --> 00:04:43,560 Why? 81 00:04:43,560 --> 00:04:46,120 Because there's 1,000 meters in 1 kilometer. 82 00:04:46,120 --> 00:04:52,920 Now you multiply 600 times 1,000 and you get 600,000 meters. 83 00:04:52,920 --> 00:04:57,720 600 kilometers is the same as 600,000 meters. 84 00:04:57,720 --> 00:05:00,320 The Egyptians would have appreciated the meter stick. 85 00:05:00,320 --> 00:05:04,440 It's better than a pharaoh's arm.