How much time you will need to calculate answer:
1) 99 * 99
2) 786 * 785
3) 76 * 45
4) 689 * 546
5) 38 * 777
6) 88 * 88
Solving any mathematics problems quickly needs calculation of Multiplication, Squares, etc. The more time we need to do calculations, the more time we will take to solve any math problem.
What if you can calculate square or multiplications in less than 20 seconds and with good practice orally as well?
We can reduce our problem-solving time for each question as 90% of problems need multiplication whether it is Work and Time, Profit and Loss, Percentage, Compound Interest, or any other topic.
We will see simple tricks to calculate:
Multiplication
1) 2 digit number * 2 digit number
2) 3 digit number * 3 digit number
3) 2 digit number * 3 digit number
4) 3 digit number * 2 number
1) Type 1: 2 digit number * 2 digit number
Question 1:
68 * 59
Solution:
| Step | Description | Calculation | Answer |
|---|---|---|---|
Step 1 | Multiply rightmost 2 digits | 8 * 9 = 72 [write 2 and carry 7] | 2 |
Step 2 | Multiply diagonal digits
and add them. | (6 * 9) + (8 * 5) =54 + 40
= 94
94 + Previous carry
94 + 7 = 101
[ write 1 and carry 10] | 12 |
Step 3 | Multiply left most 2 digit | 6 * 5 = 30
30 + Previous carry
30 + 10= 40 | 4012 |
Answer is 4012.
Question 2:
94 * 58
Solution:
| Step | Description | Calculation | Answer |
|---|---|---|---|
Step 1 | Multiply rightmost 2 digits | 4 * 8 = 32[write 2 and carry 3] | 2 |
Step 2 | Multiply diagonal digits
and add them. | (9 * 8) + (4 * 5) = 72 + 20
= 92
92 + Previous carry
92 + 3 = 95
[ write 5 and carry 9] | 52 |
Step 3 | Multiply left most 2 digit | 9 * 5 = 45
45 + Previous carry
45 + 9= 54 | 5452 |
Answer is 5452.
Question 3:
78 * 38
Solution:
| Step | Description | Calculation | Answer |
|---|---|---|---|
Step 1 | Multiply rightmost 2 digits | 8 * 8 = 64[write 4 and carry 6] | 4 |
Step 2 | Multiply diagonal digits
and add them. | (7 * 8) + (8 * 3) = 56 + 24
= 80
80 + Previous carry
80 + 6 = 86
[ write 6 and carry 8] | 64 |
Step 3 | Multiply left most 2 digit | 7 * 3 = 21
21 + Previous carry
21 + 8= 29 | 2964 |
Answer is 2964.
Question 4:
45 * 63
Solution:
Answer is 2835.
Question 5:
29 * 83
Solution:
Answer is 2407.
2) Type 2: 3 digit number * 3 digit number
Question 1:
123 * 456
Solution:
| Step | Description | Calculation | Answer |
|---|---|---|---|
Step 1 | Multiply Right-Most 2 digit | 3 * 6 = 18[write 8 and carry 1] | 8 |
Step 2 | Multiply right side
diagonal digits and add
them. | (2 * 6) + (3 * 5) = 12 + 15
= 27
27 + Previous carry
27 + 1 = 28
[ write 8 and carry 2] | 88 |
Step 3 | Multiply extreme diagonal
2 digit , middle digits and
add them | (1*6)+ (3*4) +(2*5) = 28
28 + Previous carry
28 + 2= 30
[write 0 and carry 3] | 088 |
Step 4 | Multiply left side diagonal
digits and add them. | (1*5)+(2*4) =13
13 + Previous carry
13 + 3= 16
[write 6 and carry 1] | 6088 |
Step 5 | Multiply Left Most 2 digits | 1* 4= 4
4 + Previous carry
4 + 1 = 5 | 56088 |
Answer is 56088.
Question 2:
347 * 568
Solution:
| Step | Description | Calculation | Answer |
|---|---|---|---|
Step 1 | Multiply Right-Most 2 digit | 7 * 8 = 56[write 6 and carry 5] | 6 |
Step 2 | Multiply right side
diagonal digits and add
them. | (4 * 8) + (7 * 6) = 32 + 42
= 74
74 + Previous carry
74 + 5 = 79
[ write 9 and carry 7] | 96 |
Step 3 | Multiply extreme diagonal
2 digit , middle digits and
add them | (3*8)+ (7*5) +(4*6)
= 24 + 35 + 24 = 83
83 + Previous carry
83 + 7= 90
[write 0 and carry 9] | 096 |
Step 4 | Multiply left side diagonal
digits and add them. | (3*6)+(4*5) =38
38 + Previous carry
38 + 9= 47
[write 7 and carry 4] | 7096 |
Step 5 | Multiply Left Most 2 digits | 3* 5= 15
15 + Previous carry
15 + 4 = 19 | 197096 |
Answer is 197096.
Question 3:
249 * 871
Solution:
| Step | Description | Calculation | Answer |
|---|---|---|---|
Step 1 | Multiply Right-Most 2 digit | 9 * 1 = 9
[write 9] | 9 |
Step 2 | Multiply right side
diagonal digits and add
them. | (4 * 1) + (9 * 7) = 4 + 63
= 67
67 + Previous carry
67 + 0 = 67
[ write 7 and carry 6] | 79 |
Step 3 | Multiply extreme diagonal
2 digit , middle digits and
add them | (2 * 1)+ (9 * 8) +(4 * 7)
= 2 + 72 + 28 = 102
102+ Previous carry
102 + 6 = 108
[write 8 and carry 10] | 879 |
Step 4 | Multiply left side diagonal
digits and add them. | (2 * 7)+(4 * 8) = 46
46 + Previous carry
46 + 10= 56
[write 6 and carry 5] | 6879 |
Step 5 | Multiply Left Most 2 digits | 2 * 8 = 16
16 + Previous carry
16 + 5 = 21 | 216879 |
Answer is 216879.
Question 4:
145 * 963
Solution:
Answer is 139635.
Question 5:
293 * 829
Solution:
Answer is 242897.
3) Type 3: 2 digit number * 3 digit number
Question 1:
45 * 963
Solution:
Just add extra 0 to 2 digit number and follow same procedure
Answer is 43335.
4) Type 4: 3 digit number * 2 digit number
Question 1:
145 * 63
Solution:
Just add extra 0 to 2 digit number and follow same procedure
Answer is 9135.
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