Chapter 12.1 (Mathematics 5)

Measuring Mass in Grams

Identifying the gram as a unit of measuring mass

In groups of five:

  1. Use a teaspoon to scoop dry sand or soil.
  1. Compare the mass of the sand in the tea spoon with:
    1. 14  kg sand bag.
    2. A table spoonful of soil.
      ​What do you notice?
  2. Use a beam balance to compare the mass of the teaspoonful of sand with:
    1. A piece of chalk
    2. A pencil
    3. A biro pen
    4. Coins of different denominations
      ​What do you notice?
  3. Discuss your findings with other groups.
  1. Use a weighing balance to measure the mass of one teaspoonful of sand.
  1. Divide the sand into five equal amounts.
  2. Discuss your results and share with other groups.

Note

  1. The mass of the sand in the teaspoon is about 5 grams.
  2. The mass of each of the amounts of sand is 1 gram (g).
  3. The unit of measuring mass of small objects is a gram (g).

Measuring mass in grams

Group Activity 2

In groups of five:

  1. Use teaspoonful of about 50 g of sand to make the following: 10 g, 20 g, 50 g, 100 g and 200 g of sand.
  2. Use a weighing machine or a beam balance to measure the mass of five different items in grams using the 5 grams sand bag.
  3. Fill your results in the table.

Item

Mass in grams

1.

2.

3.

4.

5.

  1. Discuss your results and share with other groups.

Number of 5 g sand bags

a) 10 grams

b) 15 grams

c) 25 grams

d) 30 grams

e) 60 grams

Estimating and measuring mass in grams

Group Activity 3

In groups of five:

  1. Collect different items with mass that can be measured in grams.
  2. Estimate and measure the mass of each item.
  3. Record the two results in a table as shown.

Item

Estimated mass in grams

Actual mass in grams

Potato

Tomato

Rubber

Mango

Maize cobs

  1. Discuss the estimated and the actual mass of each item.

Exercise C

Item

Estimated mass in grams

Actual mass in grams

Orange

Avocado

Exercise book

Textbook