4.1 Mass

Mathematics

Grade 5

Measurement and time

Module 52

Mass

Activity 1:

To solve problems that include the selection of standard units [lo 4.6]

1. As in length, it is essential that we know when to use grams, kilograms and tons as units.

Work with a friend, taking turns. Take any three objects in your class. Hold each one separately and arrange them from the lightest to the heaviest. In which unit would you weigh these items: grams? kg?; ton?

Complete the table:

DO YOU STILL REMEMBER?

1 000 g = 1 kg

1 000 kg = 1 ton

Sometimes an object can be so light that you can’t weigh it on a normal scale. Tick the objects that you think weigh less than 1 gram.

Activity 2:

To measure and record [lo 4.5.1]

To measure accurately using appropriate measuring instruments [lo 4.7.1]

DID YOU KNOW?

When we want to determine the mass of an object, it means that we want to know how heavy it is or how much it weighs . To be able to do this, we need a scale .

Please write down all the different kinds of scales you can think of:

1. Study the following scales carefully. Work with a friend and write down the reading of each scale.

1.1

1.2

1.3

1.4

1.5

1.6

2. Kyk na die volgende tekeninge en skryf die massa van die voorwerpe neer.

2. Look at the following drawings and write down the mass of each object:

2.1

2.2

2.3

2.4

Activity 3:

To estimate, measure and record [lo 4.5.1]

To measure accurately using appropriate measuring instruments [lo 4.7.1]

Work in groups of three. Bring the following items from home:

A scale; 1 cup of raw rice; 1 cup of sugar; 1 cup of flour; 1 cup of salt; 1 cup of all bran/corn flakes and 1 cup of raisins.(Remember to use the same cup each time you measure).

1. Determine the mass of each item and complete the table.

2. Which item is the heaviest?

3. Which item is the lightest?

Activity 4:

To solve problems that include selecting, calculating with and converting standard units [lo 4.6]

LET US REVISE!