Home / United States / Math Classes / 4th Grade Math / Mass and Capacity in Metric Units

We use quantities like mass and capacity to define physical objects. Mass is the amount of matter present in an object, and capacity or volume is the amount of space occupied by it. Mass and capacity can be measured in metric units or customary units. We will focus on the metric units of mass and volume for now. We will learn how to solve real-life problems related to mass and capacity with the help of some solved examples....Read MoreRead Less

Mass denotes the amount an object weighs. To find the mass we use a balance or weights. The units used in the metric system to denote mass are gram (g) and kilogram (kg). They are related as 1 kg = 1000 g or 1000 g = 1 kg.

We use grams as a unit when weighing lighter objects. When we weigh heavier objects, we use kilograms as the unit.

There is also a method to convert kilograms to grams. We multiply a gram value by 1000 to convert grams to kilograms, and to convert kilograms to grams we first convert kilograms to grams and then divide by 1000.

**For example:**

Suppose you have to convert 5 kg into grams. How would you do that?

As we know that 1kg = 1000g

⇒ 5kg = 5 × 1000g

= 5000g

Capacity is defined as the quantity of liquid that can be filled in a particular vessel.

Units in the metric system to denote capacity are: Liter (L) and milliliters (mL).

They are related as 1 L = 1000 mL or 1000 mL = 1 L.

In the Imperial system, capacity is measured in gallons as the unit.

**Example 1:**

Convert 1250 grams into kilograms.

**Solution:**

We know that, 1000 g = 1 kg

1250 g = \(\frac{1250}{1000}\)kg

= 1.25 kg

**Example 2:**

Convert 7 kilograms into grams.

**Solution:**

We know that, 1 kg = 1000 g

7 kg = 7 × 1000 g

= 7000 g

**Example 3:**

John buys a 2-Liter juice bottle from the store, and he wants to convert this quantity into milliliters. Help John convert this quantity into milliliters.

**Solution:**

We know that,

1 L = 1000 mL

⇒ 2 L = 2 × 1000 mL

= 2000 mL

**Example 4:**

Convert 4250 milliliters into Liters.

**Solution:**

We know that 1000 ml = 1 L

4250 mL = 4000 mL + 250 mL

= 4 L + \(\frac{250}{1000}\) L

= 4 L + 0.25 L

= 4.25 L

**Example 5:**

Find the equivalent mass and capacity.

- 4 kg = ________ g
- 2.4 kg = ________ g
- 3500 mL = _________ L

**Solution:**

(1) We know that 1 kg = 1000 g

⇒ 4 kg = 4 × 1000 g

= 4000 g

(2) We know that 1 kg = 1000 g

⇒ 2.4 kg = 2.4 × 1000 g

= 2400 g

(3) We know that, 1000 mL = 1 L

⇒ 3500 mL = \(\frac{3500}{1000}\)L

= 3.5 L

**Example 6:**

Noah has two eggs, one is an ostrich egg, and the other is a chicken egg. Weight of the ostrich egg is 1\(\frac{1}{2}\)kg, and that of the chicken is 500 g. Which among them weighs more?

**Solution:**

To compare quantities of different units, we convert them into a common unit and then compare the quantities.

Mass of Ostrich’s egg = 1\(\frac{1}{2}\)kg = 1.5kg

On converting it into grams, we get,

= 1.5 × 1000 g [∵ 1 kg = 1000 g]

= 1500 g

Similarly, the mass of the chicken egg = 500 g

On comparing the mass of these two eggs we get,

1500 g > 500 g

The weight of the ostrich egg is greater than that of the weight of the chicken egg.

Frequently Asked Questions on Mass & Capacity

To measure large masses there are units of mass called ** quintals** and

*1 quintal = 100 kg*

*1 metric ton = 1000 kg*

That is, 1 metric ton = 10 quintals

In metric units, liters and milliliters are used to measure capacity. But in customary units we use, quarts, gallons, cups and pints.

Also to measure the large weights there are large units of mass called quintal and Metric ton.

1 quintal = 100kg

1 metric ton = 1000kg

1 metric ton = 10 quintal = 1000kg

Commonly used units of mass are kilograms, grams and milligram.

Among them the largest unit is kilogram and the smallest unit is milligram.

A nanogram is 1 billionth of a gram. It is used in labs as a unit of measure of density in experimental results.

Ounce or ‘oz’ is the smallest unit of mass in the United States.

It weighs about the same as a slice of bread.