Using distributive property, we can perform multiplication simply.
a(b + c) = ab + ac
(a + b) (c + d) = ac + ad + bc + bd
Find the product using distributive property :
Problem 1 :
728 x 101
Solution :
728 = 700 + 28
101 = 100 + 1
728 x 101 = (700 + 28)(100 + 1)
= 700(100) + 700(1) + 28(100) + 28(1)
= 70000 + 700 + 2800 + 28
Arranging based on the number of digits, we get
= 70000 + 2800 + 700 + 28
= (72800 + 700) + 28
= 73500 + 28
= 73528
Problem 2 :
854 x 102
Solution :
854 = 800 + 54
102 = 100 + 2
854 x 102 = (800 + 54)(100 + 2)
= 800(100) + 800(2) + 54(100) + 54(2)
= 80000 + 1600 + 5400 + 108
Arranging based on the number of digits, we get
= 80000 + (1600 + 5400) + 108
= 80000 + 7000 + 108
= 87000 + 108
= 87108
Problem 3 :
258 x 1008
Solution :
258 = 200 + 58
1008 = 1000 + 8
258 x 1008 = (200 + 58)(1000 + 8)
= 200(1000) + 200(8) + 58(1000) + 58(8)
= 200000 + 1600 + 58000 + 464
Arranging based on the number of digits, we get
= 200000 + 58000 + 1600 + 464
= 258000 + 1600 + 464
= 259600 + 464
= 260064
Problem 4 :
1005 x 168
Solution :
1005 = 1000 + 5
168 = 100 + 68
1005 x 168 = (1000 + 5)(100 + 68)
= 1000(100) + 1000(68) + 5(100) + 5(68)
= 100000 + 68000 + 500 + 340
Arranging based on the number of digits, we get
= 100000 + 68000 + 500 + 340
= 168000 + 840
= 168840
Problem 5 :
The cost of a chair is ₹7635 and the cost of a table is ₹12365. Find the total cost of 12 chairs and 12 tables.
Solution :
Cost of a chair = ₹7635
Cost of table = ₹12365
Cost of 12 chairs = 12 (7635)
Cost of 12 tables = 12(12365)
Total cost = 12(7635) + 12(12365)
= 12(7635 + 12365)
= 12 (20000)
= 240000
So, the total cost of 12 chairs and tables is ₹240000.
Simplify by suitable rearrangement:
Problem 6 :
643 + 346 + 357
Solution :
= 643 + 346 + 357
Arranging in correct order.
= (643 + 357) + 346
= 1000 + 346
= 1346
Problem 7 :
5 × 241 × 20
Solution :
= 5 x 241 x 20
= 5 x 20 x 241
= 100 x 241
= 100 x (200 + 41)
= 100 x 200 + 100 x 41
= 20000 + 4100
= 24100
Problem 8 :
Simplify the following using the distributive property:
234 × 256 – 234 × 56
Solution :
234 × 256 – 234 × 56
= 234 x (256 - 56)
= 234 x 200
200 can be broken into 2 x 100
= 234 x 2 x 100
= 468 x 100
= 46800
Problem 9 :
Simplify 126 × 45 + 126 × 55 by using suitable property.
Solution :
= 126 × 45 + 126 × 55
= 126 x (45 + 55)
= 126 x 100
= 12600
Problem 10 :
Simplify using distributive property
23 x 99
Solution :
= 23 x 99
= 23 x (100 - 1)
= 23 (100) - 23(1)
= 2300 - 23
= 2277
Problem 11 :
2698 × (100+9) = 2698 × 100 + 2698 × 9
is true by _________property.
Solution :
The required property is distributive property.
Problem 12 :
Use the same property to solve the expression:
51887 × 88 + 51887 × 12
Solution :
= 51887 × 88 + 51887 × 12
= 51887 x (88 + 12)
= 51887 x 100
= 5188700
Problem 13 :
A vendor supplies 32 liters of milk to a hotel in the morning and 68 liters of milk in the evening. If the milk costs $15 per liter, how much is due to the vendor per day ?
Solution :
Quantity of milk in the morning = 32 liter
Quantity of milk delivered in the evening = 68 liters
Total quantity milk delivered = 32 + 68
= 100 liter
Cost of each liter of milk = $15
Total cost = 15 x 100
= $1500
Problem 14 :
A taxi driver filled his car petrol tank with 40 liters of petrol on Monday. The next day, he filled the tank with 50 liters of petrol cost $44 per liter, how much did he spend in all ?
Solution :
Quantity of petrol on Monday = 40 liters
On Tuesday he filled = 50 liters
Total quantity of petrol = 40 + 50
= 90 liters
Cost of 1 liter of petrol = $44
Total cost = 90 x 44
= $3960
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM