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# Measuring lengths with different units

Use different units to measure the same object.

## Measuring lengths with different units

Let's measure a fence with squirrels!

The fence is $10$ squirrels long.

Now let's measure the

**same**fence with ponies.The fence is $5$ ponies long.

### Practice problem 1

This is a rectangle.

Let's measure the ${\text{blue line}}$ below using both rectangles and a centimeter ruler:

### Practice problem 2

### Challenge question

## Want to join the conversation?

- On practice problem one, why did it ask about the width of the rectangle when it should've asked the length. Clearly the width was the same as a centimeter, and the length was shorter. When I answered shorter it said correct.(113 votes)
- The width is on the bottom, the length is on the side, that is why it is width(46 votes)

- How many inches was Raj's pencil?(3 votes)
- The whole thing here is that we don't know. If Raj had a larger pencil, the desk would be less than 8 pencils tall. If Raj sharpened his pencil a bit, the desk would be more than 8 pencils tall. We can't know exactly how tall Raj's pencil was in our normal units without knowing the height of something else in normal units, like the pen or the desk. In terms of the pen's length, Raj's pencil is 9/8 of the pen.(8 votes)

- It asks how high a desk is and Raj is 8 pencils long and Lynn is 9 and it says Raj is longer?(3 votes)
- Since Raj measures the height of a desk with his pencil, and finds out the desk is 8 pencils tall, then Lynn measures the SAME desk with her pen, and finds it is 9 pens high, Lynn's pen must be shorter than Raj's pencil. Therefore, Raj's pencil is longer than Lynn's pen.(4 votes)

- what are units?(5 votes)
- Units are specific sections or amounts of things (such as time, length, volume, etc.) that we use for measurement. Some examples of units are seconds, centimetres, and millilitres.(15 votes)

- Why is cm. shorter then in.? Who invented it?(4 votes)
- because cm = 1/100 of m and an inch is equal to 1/12 of a foot and one meter is about one yard and one yard is 3ft(6 votes)

- For the last question if Lynn's desk was 9 pens long then why was Raj's desk longer?(1 vote)
- They're measuring the same desk with different materials. Therefore, since Raj's pencil took only 8, it means that the pencil was longer.(3 votes)

- Is an inch longer than a cm?(1 vote)
- How do we know how long the pencil was? Wouldn't this answer depend on the length of the pencil?(0 votes)
- It takes 8 pencils to measure the desk. We don't need to know exactly how long the pencil is, just how many it takes to measure the desk. It took 9 pens to measure the desk. It takes more pens than pencils to measure the desk, so we know that the pen is shorter than the pencil.(1 vote)

- does anyone get problem one?(0 votes)
- Measuring the fence with squirrels and then with ponies is showing that the same object (the fence) can have different measurements when the units used to measure it are of different sizes. Kinda like how we use inches and feet, or meters and centimeters to measure things. In this case the fence is either 10 squirrels or 5 ponies long. So we also know that in this case, each pony is 2 squirrels long.(2 votes)

- is a cm longer than a inch(0 votes)
- A centimeter is shorter than an inch. In fact, you would need about 2.54 Centimeters to equal 1 inch.(1 vote)