Tenths And Hundredths Class 5 Notes Maths Chapter 10

Measurement of Length 

• The longest extent of anything measured from one end to another is called length. 
• Small length is measured in centimetres(cm),  millimetres(mm) and Decimeter (dcm) .
• Large distances are measured in metres (m) and Kilometres (km) Decameter (dm) and Hectometer(hm). 
• The standard unit of length is the metre and in short, it is written as ‘m’.
• To get Centimetre we have to divide 1 m length into 100 equal divisions and thus each division is known as a centimetre and it is written as ‘cm’. Therefore 100 cm = 1 m.
• Large distances are usually measured in kilometres. When we divide 1 km length into 1000 equal divisions and each division is termed a metre. Therefore 1000 m = 1 km. For example, we could say that Riya walks 1km every day to reach school or we could say that Riya walks 1000 m every day to reach school. 

Unit of the Length Conversion Table  

• Observe the above-mentioned conversion table. It is clear that when we move from one metric unit to another to the right, the value of the metric unit becomes ten times smaller, which is one-tenth. 
• When we move from one metric unit to another to the left in the metric chart, the value of the metric unit becomes ten times bigger.
• From the length conversion chart, different units of lengths and their equivalents are given below : 
  • 1 m = 10 dm = 1000 mm = 100 cm 
  • 1 dm = 10 cm 
  • 1 dm = 0.1 m 1 cm = 0.01 m
  • 1 mm = 0.001 m 
  • 1 km = 10 hm = 1000 m 
  • 1 hm = 10 dam = 100 m 
  • 1 dam = 10 m

Example 1: What does 0.9 cm me and convert the value into millimetres. 

We know that 1 m = 100 cm
1 cm has 10 equal parts and each part is equal to one-tenth of a centimetre.
1 millimetre is nothing but one-tenth of a centimetre.
1 mm = 1/10 cm = 0.1 cm
Hence 0.9 cm is the same as 9 millimetres.

Example 2: The school at Malappuram has its sports day. Teena jumped 3.50 m, Meena jumped 4.05 m, Rehana jumped 4.50 m, Anu jumped 3.05 m and Amina jumped 3.35 m. How far had everyone jumped in terms of metres and cm 

We know that 1 m = 100 cm
So we can write the numbers again as
Teena jumped 3 metres and 50 centimetres
Meena jumped 4 metres and 5 centimetres
Rehana jumped 4 metres and 50 centimetres
Anu jumped 3 metres and 5 centimetres
Amina jumped 3 metres and 35 centimetres. 

Example 3: Rewrite the following values in metres. 
3 metre 45 centimetre , 99 centimetre and 1 metre and 5 centimetre

We know that 1 m = 100 cm
1 cm = 0.01 m and 1 mm = 0.001 m
Now the following values can be rewritten in metres as
3 metre 45 centimetre = 3.45 m
99 centimetre = 0.99 m
1 metre and 5 centimetre = 1.05 m

Example 4: Dinesh’s mother while measuring his height said that he has to grow 45 cm more to reach 2 m height. What is Dinesh’s height in metres? 

From the question, we can say that to reach 2 m height, Dinesh has to grow 45 cm more
Dinesh's height = 2 m - 45 cm
We know that 1 m = 100 cm, hence
Dinesh's height = 200 cm - 45 cm  = 155 cm
Hence, Dinesh height is 155 cm =  1 m 55 cm 

Measurement of the Capacity of the Objects.

• Capacity is defined as the amount of liquid a container can hold and there are different units to measure the same. 
• The standard unit for measuring the capacity of anything is a litre. Litre in short is written as L.
• Millilitre(mL), Centilitre(cL), deciliter (dal), Decilitre(d), Hectolitre (hl) and Kilolitre (kL)  are the other units of measurement of capacity.
• Large quantities of liquid are usually measured in terms of Litres. For example, water-filled in a bucket will be more than a litre.
• Small quantities of liquid are measured in millilitres (mL). For example, If we have to measure the amount of coffee present in a cup or the amount of water present in a small bottle. 

Measurement Units of Capacity Related To Each Other in a Place Value System.

• The concept of a place value system for capacity is very similar to length conversion. 
• As L is the basic unit of measurement of capacity, all the other metric units are derived from L. It is clear that when we move from one metric unit to another to the left, the value of the metric units becomes ten times bigger. 
• Similarly, when we move from one metric unit to another to the right, the value becomes ten times smaller. The table given below has summarised the same.
  

Example 1: A water tank had a total capacity of 2500 Litres of water. During the daytime, 950 L 350 mL of water is pumped out of the tank. How much amount of water is left in the tank? 

From the given information we can say that
The total capacity of the tank = 2500 Litres
Total water pumped out during the daytime = 950 L 350 mL,
Therefore, water left in the tank = 2500 L - 950 L 350 mL = 1549  L= 65 mL 

Example 2: The quantity in one Dettol hand sanitiser bottle is 500 mL. What is the quantity present in 12 dozen such bottles? 

One Dettol hand sanitiser bottle contains 500 mL
We know that a dozen is nothing but a group or set of twelve.
Therefore 12 x 12 bottles contains Dettol hand sanitizer= 500 mL x 12 x 12
= 500 mL x 144
= 72000 mL or 72 litres.
Therefore a dozen of Dettol hand sanitisers have a total of 72 litres worth of hand sanitiser liquid in them. 

What is Money?

• Money is anything that helps in buying people goods and services. Money is a very important part of everyone’s daily life. Money is also called currency. 
• There are many countries in the world and every country has their currency. 
• There is a certain value that is linked with every currency and this value differs from one country to another. For example, the value of money in India will not be the same as in Srilanka.
• The currency of India is the Indian rupee denoted by the symbol ₹. 
• According to the Indian Currency. 
• 1₹ = 100 paisa
• 1 paisa = (1/100 ) rupee = 0.01 rupee 

Temperature 

• A certain degree of hotness or coldness of a body is temperature. 
• Degrees are the units which are used to measure temperature. Degrees Celsius which is represented by °C and degrees Fahrenheit which is represented by °F are a few of the different temperature scales. 
• With the help of a thermometer, the temperature of an object is measured. 
• The Fahrenheit scale ranges from 32 ° F  to 212 ° F. Water has a freezing point of 32 ° F and a boiling point of 212° F.
• The Celsius scale, also known as the centigrade scale, ranges from 0 to 100 ° C. The freezing point of water is 0° C, and the boiling point of water is 100° C.

Conversion of Temperature  

• The formula that is used to convert temperature when it  is given in degrees Celsius is, C = (F – 32) x 5/9
• The formula that is used to convert temperature when it  is given in degrees Fahrenheit is, F = 9/5 x C + 32