Cost of one ticket = Rs. 12.50
Amount to be paid for 20 students = 12.50 x 20 = Rs. 250
We have already discussed about the multiplication of decimal numbers by 10, 100 and 1000. In the same way we can find patterns for multiplying decimal numbers by 0.1, 0.01 and 0.001. Observe the following.
\(12.3\times 0.1=\cfrac { 123 }{ 10 } \times \cfrac { 1 }{ 10 } =\cfrac { 123 }{ 100 } =1.23\) 
\(12.3\times 0.01=\cfrac { 123 }{ 10 } \times \cfrac { 1 }{ 100 } =\cfrac { 123 }{ 1000 } =0.123\) 
\(12.3\times 0.001=\cfrac { 123 }{ 10 } \times \cfrac { 1 }{ 1000 } =\cfrac { 123 }{ 10000 } =0.0123\)
From the above multiplication we can conclude that, when multiplying by
• 0.1, the decimal point moves one place left.
• 0.01, the decimal point moves two places left.
• 0.001, the decimal point moves three places left.
Zeros may be needed after the decimal point as they are needed before the decimal
point of numbers when multiplied 0.1, 0.01 and 0.0001.

Area of a rectangle = l × b sq. units
Here, l = 23.5 cm, b = 1.5 cm
Area of the rectangle = 23.5 x 1.5
= 35.25 sq.cm.

i) 2.3 x 1.4
First, let us multiply 23 × 14
23 x 14 = 322
Now 2.3 x 1.4 = 3.22
(ii) 5.6  3.2
First, let us multiply 56 x 32
56 x 32 = 1792
Now 5.6 x 3.2 = 17.92

First shade 4 rows of the grid in blue colour to represent 0.4. Shade 3 columns of the grid in green colour to represent 0.3 of 0.4. Now 12 squares represents the common portion. This represents 12 hundredth or 0.12. Hence 0.3 × 0.4 = 0.12.
                \(\cfrac { 4 }{ 10 } \)                        \(\quad \cfrac { { 3 }^{ th } }{ 10 } of\cfrac { 4 }{ 10 } =\cfrac { 12 }{ 100 } \)

Underline the digit to be rounded - 2.367
Since the digit next to the underlined digit is 3 which is less than 5, the underlined digit 2 remains the same.
Also look at the number line shown below

On the number line, we observe that 2.3 is closer to 2.0 than 3.0
Hence, the rounded value of 2.367 to the nearest whole number is 2.