Square decimeter. Square Hectometers

### 1.1. Knowledge to remember

To measure area, people also use units: square decimeter, square hectare.

**a) Square decimeter**

One square decimeter (1dam^{2})

* Square decimeter is the area of a square with side length 1dam.

Square decimeter is abbreviated as dam^{2}.

• We see a square 1dam^{2} consists of 100 1 squaressquare meter^{2}.

1dam2 = 100square meter^{2}

**b) Square hectometer**

Square hectometer is the area of a square with side length 1hm

Hectometer is abbreviated as hm^{2}

1hm^{2} = 100 dam^{2}

### 1.2. Solve textbook exercises on pages 26 and 27

**Lesson 1 of the textbook page 26:**

Read area measurements:

105dam^{2}, 32 600dam^{2}, 492hm^{2}, 180350hm^{2}

**Solution guide:**

- 105dam
^{2}: One hundred and five square decimeters. - 32 600dam
^{2}: Thirty-two thousand six hundred square feet. - 492hm
^{2}: Four hundred and ninety-two square hectares. - 180350hm
^{2}: One hundred and eighty thousand three hundred and fifty square meters

Lesson 2 Textbook page 26:

Write the area measurements:

a) Two hundred and seventy-one square decimeters.

b) Eighteen thousand nine hundred and fifty-four square decimeters.

c) Six hundred and three square hectares.

d) Thirty-four thousand six hundred and twenty square meters.

__Solution guide:__

a) 271dam^{2}

b) 18594dam^{2}

c) 603hm^{2}

d) 34 620hm^{2}.

Lesson 3 Textbook page 26:

a) Write the correct number in the dot:

2dam^{2} =… m^{2} 3dam^{2} 15m^{2} = … m^{2}

200m^{2} = … dam^{2} 30hm^{2} = … dam^{2}

12hm^{2} 5dam^{2} = … dam^{2} 760m^{2} = …dam^{2} … m^{2}.

b) Write the correct fraction in the dot:

1m^{2} = … dam^{2} 1dam^{2} = … hm^{2}

3m^{2} = … dam^{2} 8dam^{2} = … hm^{2}

27m^{2} = … dam^{2} 15dam^{2} = … hm^{2}.

__Solution guide:__

Question a:

2dam2 = 200 m2 3dam2 15m2 = 315 m2

200m2 = 2 dam2 30hm2 = 30000 dam2

12hm2 5dam2 = … dam2 760m2 = 7dam2 60 m2.

Sentence b:

1m2 = \(\frac{1}{{100}}\) dam2 1dam2 = \(\frac{1}{{100}}\) hm2

3m2 = \(\frac{3}{{100}}\) dam2 8dam2 = \(\frac{8}{{100}}\) hm2

27m2 = \(\frac{27}{{100}}\) dam2 15dam2 = \(\frac{15}{{100}}\) hm2.

Lesson 4 Textbook page 27:

Write the following measurements as square decimeters (in the form):

a) 5dam^{2} 23m^{2}; b) 16dam^{2} 91m^{2} ; c) 32dam^{2} 5m^{2}.

Model: 5dam^{2} 23m^{2} = 5dam^{2} +\(\frac{23}{{100}}\) dam^{2} = 5\(\frac{23}{{100}}\) dam^{2}.

__Solution guide:__

b) 16dam2 91m2 = 16dam2 +\(\frac{91}{{100}}\) dam2 = 16\(\frac{91}{{100}}\) dam2.

c) 32dam2 5m2 = 32dam2 +\(\frac{5}{{100}}\) dam2 = 32\(\frac{5}{{100}}\) dam2.

.

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