How to Calculate Density

Density

Open Ended

What do you know about Density? Think back to what you have previously learned about density.

​Density is a measure of how much mass is in a given volume of space.

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​Observe the two boxes below.
The circles represent atoms.

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Multiple Choice

Do the two boxes have the same volume? In other words do the two boxes take up the same amount of space?

• YES

• NO

Multiple Choice

Are the two boxes filled with the same amount of matter? In other words, do they have the same amount of atoms?

• YES

• NO

Multiple Choice

If density is a mesaure of how much matter is in a given space, which box is more dense?

• The box on the left

• The box on the right

Multiple Choice

If density is a mesaure of how much matter is in a given space, why is the box on the right more dense?

• Because the box on the right is bigger than the box on the left.

• Because the box on the right has less matter inside it.

• Because the box on the right has more matter inside it.

​It is easy to see which box is more dense because you can see inside the boxes. But what if you couldn't see inside the boxes? How could you tell which box was more dense?

​

Open Ended

If you can't see inside the boxes, how do you think you could tell which was more dense? What would be your plan?

​Scientists use a formula to calculate the density of objects. It is sometimes called the love formula because it looks like a heart.

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​Density equals Mass divided by Volume.

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Multiple Choice

Density equals mass divided by volume. What does the "M" stands for in the density equation?

• Mass

• Volume

• Density

• Matter

Multiple Choice

Density equals mass divided by volume. What does the "V" stands for in the density equation?

• Mass

• Volume

• Density

• Velocity

​Look at the following word problem:

​

Amanda got 4 presents for her birthday. One present was a box that had a volume of 5cm3 and a mass of 20g. What was the density of her present? ​

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​In order to solve this problem you will have to identify the mass and volume numbers. You can tell which number is the mass number because it will have the word "grams" or a "g" behind it.

​

​

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

​

Multiple Choice

What is the mass number in the following word problem:

Amanda got 4 presents for her birthday. One present was a box that had a volume of 5cm3 and a mass of 20g. What was the density of her present?

• 4

• 5

• 1

• 20

​You can tell which number is the volume number in a word problem because it will have a "cm³" behind it.

​

​

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

​

Multiple Choice

What is the volume number in the following word problem:

Amanda got 4 presents for her birthday. One present was a box that had a volume of 5cm3 and a mass of 20g. What was the density of her present?

• 4

• 5

• 1

• 20

​Now that you have identified the mass and volume numbers it is time to enter them into the calculator.

​

​Enter the mass number into the calculator first.

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Multiple Choice

Read the word problem. Which number goes in the calculator first?

Amanda got 4 presents for her birthday. One present was a box that had a volume of 5cm3 and a mass of 20g. What was the density of her present?

• 4

• 5

• 1

• 20

​Press the divide key

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Multiple Choice

Which symbol below is the divide symbol on a calculator?

​Enter the volume number

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Multiple Choice

Read the word problem. Which number is the volume number?

Amanda got 4 presents for her birthday. One present was a box that had a volume of 5cm3 and a mass of 20g. What was the density of her present?

• 4

• 5

• 1

• 20

​Press the equal key

​

Multiple Choice

Which symbol below is the equal symbol on a calculator?

​Solve the density problem below:

​

​

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

​

Multiple Choice

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

Which number goes in the calculator first?

• 4

• 5

• 20

• 1

Multiple Choice

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

After you enter the mass number into the calculator what button on the calculator did you press next?

• Plus key

• Minus key

• Divide key

• Equal key

Multiple Choice

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

After you enter the mass number into the calculator and press the divide key, what number do you enter next?

• 4

• 5

• 20

• 1

Multiple Choice

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g. What was the density of her present?

After you enter the mass number into the calculator, press the divide key, and enter the volume number, what key do you press last?

• Plus key

• Divide key

• Equal key

• Minus key

Multiple Choice

Read the problem below. What was the density of her present?

Amanda got 4 presents for her birthday. One of the boxes had a volume of 5cm³ and a mass of 20g.

• 4

• 0.2

• 80

• 16

Multiple Choice

 

A bar of copper has a mass of 216g and a volume of 24cm³. What is the density of copper?

• 9

• 0.1

• 5184

• 240

Multiple Choice

What is the density of a plastic ball that has a volume of 6cm³ and a mass of 12g? 

• 2

• .5

• 72

• 4

Multiple Choice

Jack has a rock. The rock has a mass of 14g and a volume of 2cm³. What is the density of the rock?

• 7

• 28

• 60

• 5

Multiple Choice

What is the density of an object that has a mass of 25 g and a volume of 10.0 cm³?

• 2.5

• 5.2

• 5

• 2

​What if instead of a word problem, you were given an object and asked to calculate its density?

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​You already know that to calculate density you need to know the mass and the volume.

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Open Ended

How could you find the mass of this object?

​You could find the mass of this object by placing it on a scale. The mass of the cup is 100g

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Open Ended

How could you find the volume of this object? How much space it takes up?

​Because this is an irregular shaped object you will need to find the volume by placing the object in water.

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​The first step is to fill a graduated cylinder with enough water to cover the object.

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​Record how much water is in the graduated cylinder.

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Multiple Choice

How much water is in this graduated cylinder?

• 20 ml

• 25 ml

• 40 ml

• 10 ml

​Add the object to the water and record how much the water level rose.

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Multiple Choice

How much water is in this graduated cylinder with the object in it?

• 20 ml

• 30 ml

• 35 ml

• 40 ml

​Subtract the empty water amount from the amount with the object in it to get the cups volume.

​

​35

​minus

​25

​equals

​10

​10

Multiple Choice

A cup was placed into a graduated cylinder with 25 ml of water. The water rose as shown in the picture. What is the volume of the cup?

• 10

• 35

• 25

• 40

Multiple Choice

A 200g cup was placed in a graduated cylinder with 25 ml of water. What is the density of the cup?

• 20

• 25

• 200

• 225

Multiple Choice

An irregularly shaped piece of gold was lowered into a graduated cylinder holding a volume of water equal to 17 ml. The height of the water rose to 20 ml. If the mass of the gold was 27 g, what was its density?

• 9

• 10.5

• 6.5

• 8

Multiple Choice

An irregularly shaped stone was lowered into a graduated cylinder holding a volume of water equal to 2 ml. The height of the water rose to 7 ml. If the mass of the stone was 25 g, what was its density?

• 5

• 30

• 20

• 7.77