Weight

In this chapter, we are going to explore the topic of weight. Have you ever asked yourself why some things weigh as much as a bag filled with books while others weigh as little as a piece of paper?

What is Weight?

Weight is the measure of how heavy something is.

When you pick up a rubber ball or a football, you can feel its weight in your hand.

Heavy and Light

Heavy is a term used to describe something that has more weight.

For example: Mountains, ostriches, elephants, hippopotamuses and rhinoceros are heavy.

Light is a term used to describe something that has less weight.

For example: Feathers, balloons, paper, hair and cotton are light.

Feather has a lightweight whereas pot has a heavyweight, as shown in the figure below:

Measuring Weights

Weighing balance, beam balance and weighing scale are used to measure the weight which is displayed as follows:

Units of Weight

The weight of an object can be measured using various units of measurement such as grams, kilograms, quintals, pounds, ounces, etc.

Below is a list of some of the types of units we use:

a. Gram (g)
b. Kilogram (kg)
c. Pound (lbs)
d. Ounces (oz)

Conversions of Units of Weight

The conversion of the unit of weight is shown as:

Kilograms (kg) to Grams (g):

→ 1 kilogram (kg) is equal to 1000 grams (g).
→ To change kilograms to grams, you simply need to multiply by 1000.
→ For example, 11 kg × 1000 = 11000 g

Pound (lbs) to Ounces (oz):

→ 1 pound (lbs) is equal to 16 ounces (oz).
→ To convert pounds to ounces, you should multiply by 16.
→ For example, 3 lbs × 16 = 48 oz

Let us solve some more examples to understand them better.

Example 1: What is the weight of a jar of honey in oz if its weight is 9 lbs?

a) 94 oz
b) 124 oz
c) 144 oz
d) 164 oz

Answer: c) 144 oz

Explanation: Weight of a jar = 9 lbs (pounds)
Weight of a jar in ounces = 9 × 16
                                = 144 oz (ounces)

Example 2: The weight of a flour packet is 4 kilograms 400 grams. What is the weight of the packets shown in the figure?

a) 16 kg 200 g
b) 16 kg 400 g
c) 26 kg 400 g
d) 36 kg 400 g

Answer: c) 26 kg 400 g

Explanation: Weight of a flour packet = 4 kg 400 g
= 4 kg + 400 g
= 4 × 1000 g + 400 g
= 4000 g + 400 g = 4400 g
Weight of 6 flour packets = 4400 g × 6
= 26400 g
= 26000g + 400 g
= 26 × 1000 g + 400 g
= 26 kg + 400 g
= 26 kg 400 g