Multiplication
Multiplication is the repeated addition
The numbers that are multiplied are called factors and the answer is called the product
9 x 8 = 72
9 and 8 are factors
72 is the product
9 and 8 are factors
72 is the product
- Multiplication Tables
- Multiplication of a 3-Digit Number by a 1-Digit Number
- Multiplying a Number by 10, 20, 30, ..., 90
- Multiplying a Number by 100, 200, 300, ..., 900
- Multiplying a Number by 1
- Multiplying 2-Digit Numbers
Multiplication Tables
In class II, we learnt multiplication tables upto 6. Click here to learn it again.
| Table of 7 | Table of 8 | Table of 9 | Table of 10 |
|---|---|---|---|
| 7 x 1 = 7 7 x 2 = 14 7 x 3 = 21 7 x 4 = 28 7 x 5 = 35 7 x 6 = 42 7 x 7 = 49 7 x 8 = 56 7 x 9 = 63 7 x 10 = 70 |
8 x 1 = 8 8 x 2 = 16 8 x 3 = 24 8 x 4 = 32 8 x 5 = 40 8 x 6 = 48 8 x 7 = 56 8 x 8 = 64 8 x 9 = 72 8 x 10 = 80 |
9 x 1 = 9 9 x 2 = 18 9 x 3 = 27 9 x 4 = 36 9 x 5 = 45 9 x 6 = 54 9 x 7 = 63 9 x 8 = 72 9 x 9 = 81 9 x 10 = 90 |
10 x 2 = 20 10 x 3 = 30 10 x 4 = 40 10 x 5 = 50 10 x 6 = 60 10 x 7 = 70 10 x 8 = 80 10 x 9 = 90 10 x 10 = 100 |
Multiplication of a 3-Digit Number by a 1-Digit Number
Let's multiply 120 by 3 (without regrouping)
Step 1: Write the numbers in column form
120
x 3
Step 2: Multiply the digit in ones place with 3. 3 x 0 = 0, we write 0 in the ones place of the result.
120
x 3
0
Step 3: Multiply the digit in tens place with 3. 3 x 2 = 6, we write 6 in the tens place of the result.
120
x 3
60
Step 4: Multiply the digit in hundreds place with 3. 3 x 1 = 3, we write 3 in the hundreds place of the result.
120
x 3
360
120 x 3 = 360
120
x 3
Step 2: Multiply the digit in ones place with 3. 3 x 0 = 0, we write 0 in the ones place of the result.
120
x 3
0
Step 3: Multiply the digit in tens place with 3. 3 x 2 = 6, we write 6 in the tens place of the result.
120
x 3
60
Step 4: Multiply the digit in hundreds place with 3. 3 x 1 = 3, we write 3 in the hundreds place of the result.
120
x 3
360
120 x 3 = 360
Let's multiply 246 by 3 (with regrouping)
Step 1: Write the numbers in column form
246
x 3
Step 2: Multiply the digit in ones place with 3. 3 x 6 = 18, we write 8 in the ones place of the result and 1 in the tens place as a carry over.
1
246
x 3
8
Step 3: Multiply the digit in tens place with 3 and add the carried over 1. (3 x 4) + 1 = 13, we write 3 in the tens place of the result and 1 in the hundreds place as a carry over.
1
246
x 3
38
Step 4: Multiply the digit in hundreds place with 3 and add the carried over 1. (3 x 2) + 1 = 7, we write 7 in the hundreds place of the result.
246
x 3
738
246 x 3 = 738
246
x 3
Step 2: Multiply the digit in ones place with 3. 3 x 6 = 18, we write 8 in the ones place of the result and 1 in the tens place as a carry over.
1
246
x 3
8
Step 3: Multiply the digit in tens place with 3 and add the carried over 1. (3 x 4) + 1 = 13, we write 3 in the tens place of the result and 1 in the hundreds place as a carry over.
1
246
x 3
38
Step 4: Multiply the digit in hundreds place with 3 and add the carried over 1. (3 x 2) + 1 = 7, we write 7 in the hundreds place of the result.
246
x 3
738
246 x 3 = 738
Multiplying a Number by 10, 20, 30, ..., 90
To multiply a number by 10, 20, 30... 90, multiply the number by 1, 2, 3... 9 respectively and insert one zero on the right of the product.
| 5 x 10 | = 50 |
| 5 x 20 | = 100 |
| 5 x 30 | = 150 |
| 5 x 40 | = 200 |
| 5 x 50 | = 250 |
| 5 x 60 | = 300 |
| 5 x 70 | = 350 |
| 5 x 80 | = 400 |
| 5 x 90 | = 450 |
Multiplying a Number by 100, 200, 300, ..., 900
To multiply a number by 100, 200, 300... 900, multiply the number by 1, 2, 3... 9 respectively and insert two zeroes on the right of the product.
| 8 x 100 | = 800 |
| 8 x 200 | = 1600 |
| 8 x 300 | = 2400 |
| 8 x 400 | = 3200 |
| 8 x 500 | = 4000 |
| 8 x 600 | = 4800 |
| 8 x 700 | = 5600 |
| 8 x 800 | = 6400 |
| 8 x 900 | = 7200 |
Multiplying a Number by 1
From the multiplication table, we have
| 1 x 1 = 1 |
| 2 x 1 = 2 |
| 3 x 1 = 3 |
| 4 x 1 = 4 |
| 5 x 1 = 5 |
| 6 x 1 = 6 |
| 7 x 1 = 7 |
| 8 x 1 = 8 |
| 9 x 1 = 9 |
| 10 x 1 = 10 |
When a number is multiplied by 1, the product is the number itself.
Multiplying 2-Digit Numbers
Let's multiply 24 by 12
Step 1: Write the numbers in column form.
24
x 12
Step 2: Multiply 3 with the digit in ones place. 2 x 4 = 8, we write 8 in the ones place.
24
x 12
8
Step 3: Multiply 3 with the digit in tens place. 2 x 2 = 4, we write 4 in the tens place.
24
x 12
48
Step 4: We are done with the first digit. Now we will start with the second digit 1. Since 1 is in tens place, we start writing the product from the tens place in the next line.Multiply 1 with the digit in ones place. 1 x 2 = 4, we write 4 in the tens place.
24
x 12
48
4
Step 5: Multiply 1 with the digit in tens place. 1 x 2 = 2, we write 2 in the hundreds place.
24
x 12
48
24
Step 6: Now add the two products obtained in the above 2 steps.
24
x 12
48
24
288
24 x 12 = 288
24
x 12
Step 2: Multiply 3 with the digit in ones place. 2 x 4 = 8, we write 8 in the ones place.
24
x 12
8
Step 3: Multiply 3 with the digit in tens place. 2 x 2 = 4, we write 4 in the tens place.
24
x 12
48
Step 4: We are done with the first digit. Now we will start with the second digit 1. Since 1 is in tens place, we start writing the product from the tens place in the next line.Multiply 1 with the digit in ones place. 1 x 2 = 4, we write 4 in the tens place.
24
x 12
48
4
Step 5: Multiply 1 with the digit in tens place. 1 x 2 = 2, we write 2 in the hundreds place.
24
x 12
48
24
Step 6: Now add the two products obtained in the above 2 steps.
24
x 12
48
24
288
24 x 12 = 288