# Measuring Mass

We will discuss about measuring mass. We know that, when we put two objects in a balance scale, the pan with heavier objects always drops downwards and the pan with lighter object goes up. So, we can compare weights of two different objects using a balance and say which is heavier.

A ball and a marble are placed on the two sides of a balancing scale. We see that the ball goes down. So it is heavier. The marble moves up because it is lighter. So, in the scale, the pan carrying the heavier object moves down and the pan carrying the lighter object moves up.

We keep adding more marbles until the two pans of the balancing scale are at the same level. We say that both the ball and the marbles weigh the same now.

From the above, we can see that the ball weighs the same as the four marbles. To find out how heavy an object is, we need to weigh the object or measure the mass of the object.

Kilogram and Gram:

Kilogram is the standard unit for measuring mass. Kilogram is written as kg. We use kg to weigh heavier objects. We measure lighter objects in grams.

We know the vegetable seller is weighing potatoes in kilogram. The goldsmith is weighing a ring in grams. The wheat bags are weighing in quintals.

Some of the following weights are used like 10 kg, 5 kg, 2 kg, 1 kg, 500 g, 200 g, 100 g, 50 g etc.

The unit of weight is the gram. Kilogram is a bigger unit of weight.

1 kilogram is equal to 1000 grams

or

1000 grams is equal to 1 kilogram

We write gram as 'g' and kilogram as 'kg' in short form.

1 kg is equal to 1000 g

or

1000 g is equal to 1 kg

Kilogram is the standard unit for measuring mass. Kilogram is written as kg. We use kg to weigh heavier objects. We measure lighter objects in grams.

Questions on Measuring Mass:

1. Circle the heavier object in each pair.

2. Write the unit of weight in which we will use to measure the following:

(i) eraser

(ii) biscuit packet

(iii) four toffees

(v) soap-bar

(vi) gold ring

(vii) bag of rice

Suhani and her mother are sitting on the opposite ends of a see-saw.

Who is heavier among the two?

__________ is heavier.

Now Suhani and her brother Ishan are sitting on opposite ends of a see-saw.

Tick (✔) the correct statement.

Ishan is heavier than Suhani.

Suhani is heavier than Ishan.

Suhani and Ishan have same weight.

Now Suhani and Ishan are sitting together on one end while their mother is sitting on the opposite end of the see-saw.

Tick (✔) the correct statement.

The combined weight of Suhani and Ishan is more than the weight of their mother.

The weight of their mother is more than the combined weight of Suhani and Ishan.

The combined weight of Suhani and Ishan is exactly the same as the weight of their mother.

Extra questions for sharp students on measuring mass!

3. Find the total weight in kg. 2 kg sugar, 3 kg flour and 1 kg onion.

2. Sam weighs 45 kg and Aaron weighs 56 kg. What is their total weight?

3. John bought 2 kg apples, 4 kg mangoes, 1 kg pears and put them in his bag. Find the total weight of the fruits in his bag.

4. Three brothers weigh 30 kg, 25 kg and 45 kg. Find their total weight.

5. A man weighs 72 kg and his wife weighs 59 kg. How much does the man weigh more than his wife?

6. Papaya sells at \$16 per kg. Find the cost of 4 kg of these papayas.

7. A bag of wheat weighs 25 kg. Find the total weight of 8 such bags.