Multiplying by 10
Multiply any number by 10 is easy, simply multiply by 1 and add Zero at the end OR move the decimal point one space to the right. For example, 83.45 * 10 = 834.5
- 10 * 1 is 10
- 10 * 2 is 20
- 10 * 3 is 30
- 10 * 4 is 40
- 10 * 5 is 50
- 10 * 6 is 60
- 10 * 7 is 70
- 10 * 8 is 80
- 10 * 9 is 90
- 10 * 10 is 10
- 10 * 11 is 110
- 10 * 12 is 120
Multiplying by 100
To multiply a number by 100 is easy, just add 00 after the number OR move the decimal point to two spaces right 789.568 * 100 =78956.8
- 100 * 1 is 100
- 100 * 2 is 200
- 100 * 3 is 300
- 100 * 4 is 400
- 100 * 5 is 500
- 100 * 6 is 600
- 100 * 7 is 700
- 100 * 8 is 800
- 100 * 9 is 900
- 100 * 10 is 100
- 100 * 11 is 1100
- 100 * 12 is 1200
Multiplying two digit by one digit numbers
- First line up the numbers as per the place value (all the tens and the units lined up vertically). Put a line under the last number.
52 3- Multiply the numbers in ones place (2 * 3 = 6). Write the answer in the ones place column.
52 3 6- Multiply the number in the tens place column (5) by the number in the lower ones place column (3). The answer is 5 * 3 = 15. Write the answer below the line in the tens place column.
52 3 156
Multiplying two digit by one digit numbers
How to multiply a two-digit number by a one-digit number?
- First line up the numbers as per the place value (all the tens and the units lined up vertically). Put a line under the last number.
78 5- Multiply the two ones digit numbers (8 * 5 = 40). This result is greater than 9, so write the 4 above the tens place value and write the 0 under the line in the ones place column.
4 78 5 0- Multiply the digit in the tens place column (7) by the lower ones place digit (5). The result is 7 * 5 = 35. Add 4 to 35 (35 + 4 = 39) and write the answer under the line and to the left of the 3.
4 78 5 390
Multiplication of Two and Three Digit Numbers
How to multiply a three-digit number by a two-digit number (e.g. 649 * 76)?
- First line up the numbers as per the place value (all the hundreds, tens and the ones lined up vertically). Draw a line under the last number.
649 76- Multiply the numbers in ones place. (9 * 6 = 54). The result 54 is greater than 9 so write a 5 above the tens place value and write 4 under the line in the ones place column
5 649 76 4- Multiply the digit in the tens place column that is 4 by the number in the lower ones place column that is 6. The result is (4*6=24). Now Add 5 to 24 (24 + 5 = 29) and write 9 in the tens place column below the line and 2 above the hundreds place column.
25 649 76 94- Multiply the digit in the hundreds place column (6) by the number in the lower ones place column (6). The result is (6*6=36). Now Add 2 to 36 (36 + 2 = 38) and write 38 under the line to the left of 9.
25 649 76 3894- After 649 has been multiplied by 6 as shown above, 649 is multiplied by the number in the lower tens'' place, which is 7. The number is shifted one place to the left because we are multiplying by a tens' place value. The result will be 4543:
25 649 76 3894 4543- Draw a line under the lower product (4543) and the products are now added together to get the final result of 49324.
25 649 76 3894 4543 49324
Multiplying three digit by one digit numbers
How to multiply a three-digit number by a one-digit number (e.g. 524 * 2)?
- First line up the numbers as per the place value (all the tens and the units lined up vertically). Put a line under the last number.
524 2- Multiply the numbers in the ones place (4 * 2 = 8). Write the 8 under the line in the ones place column.
524 2 8- Multiply the number in the tens place column that is 2 by the number in the lower ones place number that is 2. The result is 2 * 2 = 4. Write the answer under the line and to the left of the 8.
524 2 48- Multiply the number in the hundreds place column that is 5 by the lower tens place number which is 2. The result is 5 * 2 = 10. Write the 10 under the line in the hundreds'' place column.
524 2 1048
If any number is multiplied by 0, answer is 0.
If any number is multiplied by 1, answer is that number.
Multiplying by 2 and 3
TWO | ||||
0*2=0 | 1*2=2 | 2*2=4 | 3*2=6 | 4*2=8 |
THREE | ||||
0*3=0 | 1*3=3 | 2*3=6 | 3*3=9 | 4*3=12 |
How to multiply two numbers (for example 46 * 78) with a calculator?
- Type the first number by pressing the 4 button and the 6 button.
- Press the * operation button.
- Type the number 78 by pressing the 7 button and the 8 button.
- Press the = button to get the result.
Try some yourself:
Exercise 1
- 143 * 8 =
- 434 * 233 =
- 767 * 5 =
- 555 * 245 =
- 7878 * 98 =
- 6578 * 10 =
- 56 * 5 =
- 2323 * 57 =
- 888 * 321 =
- 567 * 38 =
Answers to exercise 1
- 1144
- 101122
- 3835
- 135975
- 772044
- 65780
- 280
- 132411
- 285048
- 21546