Multiplication
In the previous class, we have learnt multiplication up to 4-digit numbers by 1-digit and 2-digit numbers. In this class, we will learn more about multiplication.
Multiplication by 1 -digit number
Example: Multiply the following:
Multiplication by 2 -digit numbers
Example: Multiply the following
Multiplication by 3 digit numbers
Example: Multiply the following:
Multiplication problems in daily life
1.The capacity of a drum is 60 liters of milk. How much milk can be collected in 7 drums of such capacity?
Answer: 7 Drums can hold 420 litres
2.The cost of a chair is ₹315. Find the cost of 27 such chairs.
Answer: The cost of 27 chairs is 8505 ₹
3.The weight of one bag of rice is 89 kg. What is the weight of 91 such bags?
Answer: 91 bags can hold 8099 kg rice.
Properties of Multiplication
Property 1: Commutative : The product of two numbers does not change if the order of the numbers is altered, according to this property.
For example: 500 × 253 = 126500 or 253 × 500 = 126500
Property 2: Associative : This property means that if you multiply three or more numbers together, it doesn’t matter how you group them, the result will always be the same.
For example: (253 × 25) × 3 = 6325 × 3 = 18975
Or
253 × (25 × 3) = 253 × 75 = 18975
Property 3: This property means that when you multiply any number by 1, the result is that same number.
Example: 897 × 1 = 897, 14979 × 1 = 14979, 52351 × 1 = 52351
Property 4: This property means that when you multiply any number by 0, the result is 0.
Example: 897 × 0 = 0, 14979 × 0 = 0, 52351 × 0 = 0
Property 5: This property means that when you multiply a number by the sum of two or more other numbers, it’s the same as multiplying each number by that same number and then adding the results together.
Example: 40 × 54 = 2160
or 40 × (50 + 4) = 40 × 50 + 40 × 4
= 2000 + 160
= 2160
So, 40 x 54 = 40 × (50 + 4) = 2160