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STANDARDS
CCSS: 5.NBT.A.4
TEKS: 5.2C, 5.3A
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Courtesy of Inmotion (Unicycle)
This unicycle requires no pedaling!
Zip around town on an electric unicycle—no pedaling required! The V5F is 70 centimeters wide and weighs only as much as a baby stroller. Its thin and foldable design makes it easy to store and carry. The battery-powered unicycle can travel almost 40 kilometers on a single charge.
Ride around town on an electric unicycle. You won’t need to pedal! The V5F is 70 centimeters wide and weighs only as much as a baby stroller. It’s thin and can fold up. That makes it easy to store and carry. It’s also battery powered. It can travel almost 40 kilometers on a single charge.
With the Waymo One ride service, the only humans in the car are passengers! The company has been testing its driverless car service since 2018 in Phoenix, Arizona. It serves an area of almost 260 square kilometers. Waymo aims to make travel via car easier and safer. Riders can even request multiple stops per trip.
The cars use cameras and radar to detect other vehicles and objects and avoid hitting them. Waymo recently began testing a new self-driving service in San Francisco, California.
With the Waymo One ride service, the only humans in the car are passengers! The company has been testing its driverless car service since 2018 in Phoenix, Arizona. It serves an area of almost 260 square kilometers. Waymo’s goal is to make travel by car easier and safer. Riders can even request multiple stops per trip.
Courtesy of Waymo
Cameras sense objects so the car can react.
Richard Browning zooms through the air thanks to a special suit that he invented. Called the Gravity Jet Suit, it looks like a high-tech backpack with jet engine sleeves! The suit includes five engines that allow Browning to zoom up to 90 kilometers per hour.
Browning intends to use his invention for entertainment, not travel. He and his team are organizing a jet suit racing league. Pilots fly through an obstacle course floating on water.
Richard Browning zooms through the air thanks to a special suit that he invented. It’s called the Gravity Jet Suit. The suit looks like a high-tech backpack with jet engine sleeves! Its five engines allow Browning to fly up to 90 kilometers per hour.
Browning plans to use his invention for entertainment, not travel. He and his team are organizing a jet suit racing league. Pilots will fly through an obstacle course floating on water.
Guy Corbishley/Alamy Stock Photo
Jet engines control your flight.
An ultrafast system of pods pushed through tubes might sound like science fiction, but it’s real! A hyperloop is a high-speed transit system that runs underground. It can move people and things from place to place faster than a plane.
The Virgin Hyperloop successfully transported passengers in a 2020 test run. However, it is not fully complete yet. The Virgin Hyperloop only runs in a straight line and cannot turn corners. For now, it transports only cargo, not human passengers. But if this form of high-speed travel can be perfected, people will zoom over land 10 times faster than a typical commuter train.
A very fast system of pods pushed through tubes might sound like science fiction. But it’s real! A hyperloop is a high-speed transit system that runs underground. It can move people and things from place to place faster than a plane.
The Virgin Hyperloop successfully transported passengers in a 2020 test run. However, it is not fully complete yet. The Virgin Hyperloop runs only in a straight line. It can’t turn corners. For now, it transports only cargo. But if this form of high-speed travel can be perfected, people will zoom over land 10 times faster than a train.
Courtesy of Virgin Hyperloop
A hyperloop test pod is 10 times faster than a typical train.
What are some limitations to using rounding and estimates? When might they not be an appropriate tool?
What to Do
Estimation can make complex calculations quicker and easier. Estimations use friendly, rounded numbers to make calculations close to the actual value. A place value chart shows the value of each digit in a number based on its position. It can help you round decimals to more friendly numbers. This makes decimal numbers easier to work with when you don’t have to be exact.
Remember, when finding an estimate,round before performing an operation.
Example
A 9.6-hour trip by plane takes only 6.183 hours by a high-speed transportation system called a hyperloop. Estimate the time saved traveling by hyperloop.
6 tenths is closer to 1 than to 0, so 9.6 rounds up to 10 1 tenth is closer to 0 than to 1, so 6.183 rounds down to 6
10 hours – 6 hours = 4 hours
So traveling by hyperloop on this trip saves about 4 hours.
Now You Try It
The V5F electric unicycle takes 3.5 hours to charge.
A. To make 3.5 a friendly number, what place value should we round to?
B. What is 3.5 rounded to the place value you chose above?
A rider takes a Waymo car 5.62 kilometers to the library. Then he travels another 3.12 km to a store.
A. Round each distance to the nearest whole number.
B. Use the rounded distances to estimate the total distance traveled.
The combined weight of the jet suit and fuel is 35 kilograms. A pilot who weighs 88.7 kilograms puts on the suit.
A. Round each weight to the nearest ten.
B. Use the rounded weights to estimate the combined weight of the pilot and suit.
C. The pilot calculated a combined weight of 92.2 kg. Compare your estimate with the pilot’s calculation. Is his calculation reasonable?
If built, a hyperloop journey from Houston, Texas, to New York City would take 2.626 hours. The same journey would take 3.53 hours by plane.
A. Round these times to the nearest tenth.
B. Estimate the time difference using your rounded times.
C. Determine the actual difference in time. How does your estimate compare to the actual difference in time?
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