Multiplying 2-Digit Number by 1-Digit Number

Here we will learn multiplying 2-digit number by 1-digit number. In two different ways we will learn to multiply a two-digit number by a one-digit number.


Examples of multiplying 2-digit number by 1-digit number without Regrouping:

We will have a quick review of multiplication of 2-digit number by 1-digit number without regrouping:

1. Multiply 24 by 2.

               T     O

               2     4

            ×        2

               4     8

First multiply the ones by 2.

× 2 = 8.

Write 8 under O.

Now multiply the tens by 2.

3 × 3 = 9.

Write 9 under T.


2. Multiply 34 and 2

Solution:

Step I: Arrange the numbers vertically.

Step II: First multiply the digit at the ones place by 2.

2 × 4 = 8 ones

Step III: Now multiply the digit at the tens place by 2.

2 × 3 = 6 tens

Multiplying 2-Digit Number by 1-Digit Number

Thus, 34 × 2 = 68


3. Multiply 20 by 3 by using expanded form

Solution:

                   20         →                           2 tens + 0 ones

              ×    3         →                                       ×      3

                                                            6 tens + 0 ones

                                                          = 60 + 0

                                                          = 60

Therefore, 20 × 3 = 60


4. Multiply 50 by 1 by using short form

Solution:

         50                      →                50                     

    ×    1                      →             ×   1

          0                                           50

(i) First digit of one’s place is multiplied by 1, i.e., 0 × 1 = 0

(ii) Then digit at ten’s place is multiplied by 1, i.e., 5 tens × 1 = 5 tens

Hence, 50 × 1 = 50


Observe the following Example using Three Different Methods:

5. Multiply 13 by 2.

Solution:

First Method: Using Repeated Addition.

13 x 2 = 13 + 13 = 26

Therefore, 13 x 2 = 26.


Second Method: Using Expanded Form

Consider 13 as 10 + 3.

13 × 2 = (10 + 3) × 2

           = 10 × 2 + 3 × 2

           = 20 + 6

           = 26.


Third Method: Short Form

Write the numbers according to place value shown on the right.

Step I:

Multiply the ones:

3 ones × 2 = 6 ones

Write 6 under ones column.


Step II:

Multiply the tens:

1 ten × 2 = 2 tens

Write 2 under tens column.

Thus, the product of 13 and 2 is 26.


Examples of multiplying 2-digit number by 1-digit number with Regrouping:

1. Multiply 66 by 3

               T     O

               1

               6     6

            ×        3

        1     4     8

First multiply the ones by 3.

× 3 = 18 = one ten + 8 ones

Write 8 under O. carry 1 ten

Now multiply the tens by 3.

6 × 3 = 18

Add 1 to the product.

18 + 1 = 19


2. Multiply 25 by 3

Step I: Arrange the numbers vertically.

Step II: First multiply the digit at the ones place by 3.

3 × 5 = 15 = 1 ten + 5 ones

Write 5 in the ones column and carry over 1 to the tens column

Step III: Now multiply the digit at the tens place by 3.

3 × 2 = 6 tens

Now, 6 + 1 (carry over) = 7 tens

Multiplying 2-Digit Number by 1-Digit Number with Regrouping

Thus, 25 × 3 = 75


3. Multiply 46 by 4

Step I: Arrange the numbers vertically.

Step II: Multiply the digit at the ones place by 4.

6 × 4 = 24 = 2 tens + 4 ones

Write 4 in the ones column and carry over 2 to the tens column

Step III: Now multiply the digit at the tens place by 4.

4 × 4 = 16 tens

Now, 16 + 2 (carry over) = 18 tens = 1 hundred + 8 tens

Write 8 at the tens place and 1 at the hundred place.

Multiply 2-Digit Number by 1-Digit Number with Regrouping

Thus, 46 × 4 = 184


4. Multiply 20 by 3 by using expanded form

Solution:

                   20         →                           2 tens + 0 ones

              ×    3         →                                       ×      3

                                                            6 tens + 0 ones

                                                          = 60 + 0

                                                          = 60

Therefore, 20 × 3 = 60


5. Multiply 26 by 7 by using expanded form 

Solution:

              26          →       20 + 6          →           2 tens + 6 ones

       ×      7          →         ×   7           →                          ×     7

                                                             (2 × 7) tens + (6 × 7) ones


        2 tens + 6 ones

×                  7 ones

   14 tens + 42 ones

= 14 tens + (40 + 2) ones

= 14 tens + 4 tens + 2 ones

= 18 tens + 2 ones

= 180 + 2

= 182

Therefore, 26 × 7 = 182


6. Multiply 48 by 6 by using short form

Solution:

                 48

        ×         6

         24 ← 48

= 28 tens 8 ones

= 288

Hence, 48 × 6 = 288

(i) 48 × 6 is written in column from.

(ii) 8 ones are multiplied by 6, i.e., 6 × 8 = 48 ones = 4 tens + 8 ones

8 is written is one’s column and 4 tens is gained.

(iii) Gained 4 is carried to the ten’s column.

(iv) Now 4 tens is multiplied by 6, i.e., 4 tens × 6 = 24 tens

(v) Carried 4 tens is added to 24 tens, i.e., 4 tens + 24 tens = 28 tens


7. Find the product of 58 × 5.

Solution:

                 58

              ×   5

          25 ← 40 

 = 25 + 4 ← 0

 = 29          0

 = 290

(i) 8 ones × 5 = 40 = 4 tens + 0 one

(ii) 5 tens × 5 = 25 tens

(iii) 25 tens + 4 tens = 29 tens

Hence, 58 × 5 = 290


8. Multiply 37 by 8

Solution:

                3  7

        ×          8

               5   6

     +   2   4   0

          2   9    6

(i) 7 ones × 8 = 56 ones = 5 tens 6 ones

56 is placed in such way that 5 comes under tens and 6 under ones

(ii) 3 tens × 8 = 24 tens = 240 ones

= 2 hundreds, 4 tens and 0 ones

240 is placed below 56 in such way that 2 comes under hundreds, 4 under tens and 0 under ones.

Hence, 37 × 8 = 296


Questions and Answers on Multiplying 2-Digit Number by 1-Digit Number:

Multiplication of 2-Digit Number by 1-Digit Number Without Regrouping:

I. Find the product:

(i) 23 × 3 =

(ii) 44 × 2 =

(iii) 33 × 2 =

(iv) 22 × 4 =

(v) 32 × 3 =

(vi) 40 × 2 =

(vii) 43 × 2 =

(viii)  12 × 3 =

(ix) 23 × 2 =

(x) 11 × 9 =

(xi) 21 × 4 =

(xii) 13 × 3 =


Answer:

I. (i) 69

(ii) 88

(iii) 66

(iv) 44

(v) 96

(vi) 80

(vii) 86

(viii) 36

(ix) 46

(x) 99

(xi) 84

(xii) 39


Multiplication of 2-Digit Number by 1-Digit Number With Regrouping:

II. Find the product:

(i) 46 × 2

(ii) 19 × 4

(iii) 27 × 3

(iv) 18 × 5


Answer:

II. (i) 92

(ii) 76

(iii) 81

(iv) 90


III. Multiply the following:

(i) 78 × 4

(ii)  63 × 6

(iii) 51 × 6

(iv) 39 × 8

(v) 72 × 9

(vi) 45 × 7

(vii) 17 × 4

(viii) 88 × 8


Answer:

III. (i) 312

(ii)  398

(iii) 306

(iv) 312

(v) 648

(vi) 315

(vii) 68

(viii) 704


IV. Solve the following:

(i) 37 × 6

(ii) 72 × 4

(iii) 56 × 7

(iv) 84 × 2

(v) 45 × 9


Answer:

IV. (i) 37 × 6

(ii) 72 × 4

(iii) 56 × 7

(iv) 84 × 2

(v) 45 × 9


V. Multiply the following :

(i)

                    T     O

                    3     1

                    ×    2 

                 _______

(ii)

                    T     O

                    4     7

                    ×    1 

                 _______

(iii)

                    T     O

                    1     1

                    ×    3 

                 _______

(iv)

                    T     O

                    2     2

                    ×    2 

                 _______

(v)

                    T     O

                    2     3

                    ×    2 

                 _______

(vi)

                    T     O

                    2     6

                    ×    3 

                 _______

(vii)

                    T     O

                    4     9

                    ×    2 

                 _______

(viii)

                    T     O

                    2     3

                    ×    4 

                 _______

(ix)

                    T     O

                    1     6

                    ×    6 

                 _______

(x)

                    T     O

                    1     9

                    ×    5 

                 _______

(xi)

                    T     O

                    5     2

                    ×    5 

                 _______

(xii)

                    T     O

                    2     3

                    ×    6 

                 _______

(xiii)

                    T     O

                    6     4

                    ×    9 

                 _______

(xiv)

                    T     O

                    3     2

                    ×    7 

                 _______

(xv)

                    T     O

                    7     5

                    ×    8 

                 _______

Answer:

III. (i) 62

(ii) 47

(iii) 33

(iv) 44

(v) 46

(vi) 78

(vii) 98

(viii) 92

(ix) 96

(x) 95

(xi) 260

(xii) 138

(xiii) 576

(xiv) 224

(xv) 600


VI. Multiply the following:

(i) 21 × 5 = _____

(ii) 34 × 2 = _____

(iii) 23 × 3 = _____

(iv) 27 × 3 = _____

(v) 38 × 2 = _____

(vi) 18 × 4 = _____

(vii) 25 × 8 = _____

(viii) 32 × 6 = _____

(ix) 29 × 4 = _____

(x) 45 × 5 = _____


Answer:

VI. (i) 105

(ii) 68

(iii) 69

(iv) 81

(v) 76

(vi) 72

(vii) 200

(viii) 192

(ix) 116

(x) 225


VII. Find the following products in your notebook.

(i)

                    T     O

                    2     9

                    ×    7 

                 _______

(ii)

                    T     O

                    6     3

                    ×    4 

                 _______

(iii)

                    T     O

                    3     8

                    ×    7 

                 _______

(iv)

                    T     O

                    6     6

                    ×    4 

                 _______

(v)

                    T     O

                    5     4

                    ×    7 

                 _______

(vi)

                    T     O

                    3     5

                    ×    4 

                 _______

(vii)

                    T     O

                    6     9

                    ×    8 

                 _______

(viii)

                    T     O

                    8     5

                    ×    4 

                 _______

(ix)

                    T     O

                    8     0

                    ×    4 

                 _______

(x)

                    T     O

                    5     8

                    ×    8 

                 _______

(xi)

                    T     O

                    5     1

                    ×    7 

                 _______

(xii)

                    T     O

                    6     3

                    ×    8 

                 _______


Answer:

VIII. (i) 203

(ii) 252

(iii) 266

(iv) 264

(v) 378

(vi) 140

(vii) 552

(viii) 340

(ix) 320

(x) 464

(xi) 357

(xii) 504



VIII. Find the products:

(i) 27 × 4 = __________

(ii) 5 × 10 = __________

(iii) 25 × 9 = __________

(iv) 16 × 4 = __________

(v) 14 × 8 = __________ 

(vi) 37 × 7 = __________

(vii) 63 × 4 = __________

(viii) 2 × 70 = __________

(ix) 53 × 5 = __________


Answer:

VIII. (i) 108

(ii) 50

(iii) 225

(iv) 64

(v) 112

(vi) 259

(vii) 252

(viii) 140

(ix) 265


IX. Word Problem on Multiplying 2-Digit Number by 1-Digit Number:

(i) A month has 30 days. How many days be there in 3 such months?

Answer:

IX. (i) 90 days

You might like these






2nd Grade Math Practice

From Multiplying 2-Digit Number by 1-Digit Number to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.



New! Comments

Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.

Share this page: What’s this?

Recent Articles

  1. Formation of Greatest and Smallest Numbers | Arranging the Numbers

    May 19, 24 03:36 PM

    Formation of Greatest and Smallest Numbers
    the greatest number is formed by arranging the given digits in descending order and the smallest number by arranging them in ascending order. The position of the digit at the extreme left of a number…

    Read More

  2. Formation of Numbers with the Given Digits |Making Numbers with Digits

    May 19, 24 03:19 PM

    In formation of numbers with the given digits we may say that a number is an arranged group of digits. Numbers may be formed with or without the repetition of digits.

    Read More

  3. Arranging Numbers | Ascending Order | Descending Order |Compare Digits

    May 19, 24 02:23 PM

    Arranging Numbers
    We know, while arranging numbers from the smallest number to the largest number, then the numbers are arranged in ascending order. Vice-versa while arranging numbers from the largest number to the sma…

    Read More

  4. Comparison of Numbers | Compare Numbers Rules | Examples of Comparison

    May 19, 24 01:26 PM

    Rules for Comparison of Numbers
    Rule I: We know that a number with more digits is always greater than the number with less number of digits. Rule II: When the two numbers have the same number of digits, we start comparing the digits…

    Read More

  5. Worksheets on Comparison of Numbers | Find the Greatest Number

    May 19, 24 10:42 AM

    Comparison of Two Numbers
    In worksheets on comparison of numbers students can practice the questions for fourth grade to compare numbers. This worksheet contains questions on numbers like to find the greatest number, arranging…

    Read More