Chapter 12.2 (Mathematics 5)

The Kilogram and the Gram

Relationship between the kilogram and the gram

In groups of five:

  1. Use a teaspoon to measure 5 g of sand.
  2. Use the teaspoon to measure 200 g of sand.
  3. Put the 200 g sand in a packet.
  4. Make five such packets. What is the mass of the five packets in grams?
    Answer.  grams
  5. Balance the five packets of sand with a 1 kg stone. What do you notice?
    Answer. 5 packets of sand   than 1 kg stone. 
  6. Discuss the results and share with other groups.

Note

1 kg = 1000 g

Exercise D

Answer.  packets

Conversion of kilograms to grams

Example 1a

Convert 2 kg into grams

  1. 1 kg = 1 000 g
  2. 2 kg = 2 × 1 000 g = 2 000 g

Example 1b

Convert 3 kg 250 g into grams

  1. 1 kg = 1 000 g
  2. 3 kg = 3 × 1 000 g = 3 000 g
  3. 3 kg 250 g = 3 000 g + 250 g = 3 250 g

Exercise E

Kg

1

2

3

4

g

5

6

7

8

9

  1. 11 kg =  g
  2. 17 kg =  g 
  3. 23 kg =  g
  4. 35 kg =  g
  1. 5 kg 350 g =  g
  2. 12 kg 70 g =  g 
  3. 20 kg 750 g =  g

Answer. The mass was  grams.

Answer. The mass was  grams.

Conversion of grams to kilograms

Example 2a

Convert 5 000 grams to kilograms

  1. 1 000 g = 1 kg
  2. 5 000 g = 5 × 1 000 g =
    = ​5 × 1 kg = 5 kg

Example 2b

Convert 8 650 g into kilograms

  1. 1 000 g = 1 kg
  2. 8 650 g = 8 000 g + 650 g =
    =​ 8 × 1 000 g + 650 g =
    =​ 8 × 1 kg + 650 g =
    =​ 8 kg 650 g

Exercise F

Grams

1 000

2 000

3 000

4 000

Kilo­grams

5 000

6 000

7 000

8 000

9 000

  1. 11 000 g =  kg
  2. 15 000 g =  kg
  3. 27 000 g =  kg
  4. 42 000 g =  kg
  1. 3 270 g =  kg  g
  2. 5 750 g =  kg  g
  3. 9 080 g =  kg  g
  4. 12 000 g =  kg  g
If answer is 0, leave the gap blank.

Answer. The mass of the baby was
  kg  g.

Answer. The mass of packed lunch was
  kg  g.