Study P4 Mathematics Maths - Multiplication - Geniebook

Multiplication

In this article, the lesson objectives are: 

  1. Multiplication of \(4-\)digit numbers by \(1-\)digit numbers
  2. Multiplication by \(10\) and its multiples
  3. Multiplication of \(2-\)digit numbers by \(2-\)digit numbers
  4. Multiplication of \(3-\)digit numbers by \(2-\)digit numbers

In Primary \(2\) and \(3\), we have learnt the multiplication tables of \(1\) to \(10\)

 

Question 1: 

Solve the following multiplication.

\(8 × 9 =\) __________

 

  1. \(54\)
  2. \(56\)
  3. \(64\)
  4. \(72\)

 

Solution:  

\(8 \times 9 = 72\)

Answer:

\((4) \;72\)

 

 

Question 2: 

Solve the following multiplication.

\(18 \times 7 =\) __________

 

  1. \(124\)
  2. \(126\)
  3. \(134\)
  4. \(136\)

 

Solution:

Answer: 

\((2) \;126\)

 

 

1. Multiplication Of 4-Digit Numbers By 1-Digit Numbers

The multiplication of \(4-\)digit numbers by \(1-\)digit numbers is similar to the multiplication of \(3-\)digit numbers by \(1-\)digit numbers.

 

Example:

\(1936 × 7 =\) __________   

 

Solution: 

Step 1:

Step 2:

Step 3:

Step 4:

Answer:

\(13 \,552\)

       

 

Question 1: 

Solve the following multiplication.

\(3918 \times 5 =\) __________  

 

Solution:   

Answer:

\(19 \,590\)


 

2. Multiplication By 10 And Its Multiples

When we multiply a whole number by \(10\), we add one ‘\(0\)’ after the number. 

For instance, 

\(\begin{align*}​ 5 \times 10 &= 50 \\ 15 \times 10 &= 150 \\ 215 \times 10 &= 2150 \end{align*}\)

What do you think happens when we multiply a whole number to a multiple of \(10\)?

We express the multiple as a product of \(10\) and a number.

 

Let’s try the following.

Example:

\(5 \times 30 =\) __________

 

Solution:

We express \(30\) as a product of \(3\) and \(10\).

\(\begin{align*}​ 5 \times 30 &= 5 \times 3 \times 10 \\ &= 15 \times 10 \\ &= 150 \end{align*}\)

Answer:

\(150\)

 

 

Question 1: 

Solve the following multiplication.

\(22 \times 10 =\) __________

 

Answer:

\(220\)

 

 

Question 2: 

Solve the following multiplication.

\(51 \times 10 =\) __________

 

Answer: 

\(510\)

 

 

Question 3: 

Solve the following multiplication.

\(38 \times 50 =\) __________

 

Solution:


\(\begin{align*}​ 38 \times 50 &= 38 \times 5 \times10 \\ &= 190 \times 10 \\ &= 1900 \end{align*}\)

Answer: 

\(1900\)

 

 

Question 4: 

Solve the following multiplication.

\(94 \times 50 =\) __________

 

Solution: 


\(\begin{align*}​ 94 \times 50 &= 94 \times 5 \times 10 \\ &= 470 \times 10 \\ &=4700 \end{align*}\)

Answer: 

\(4700\)

 

 

Question 5: 

Solve the following multiplication.

\(74 \times 60 =\) __________

 

Solution: 


\(\begin{align*}​ 74 \times 60 &= 74 \times 6 \times 10\\ &= 444 \times 10\\ &= 4440 \end{align*}\)

Answer:

\(4440\)

 

 

Question 6: 

Solve the following multiplication. 

\(1059 × 90 =\) __________

 

Solution:


\(\begin{align*}​ 1059 \times 90 &= 1059 \times 9 \times 10 \\ &= 9531 \times 10 \\ &= 95 310 \end{align*}\)

Answer:

\(95 \,310\)

 

 

3. Multiplication Of 2-Digit By 2-Digit Numbers

Now, let’s multiply a \(2-\)digit number by a \(2-\)digit number.

Step 1: 

We multiply the first number by the digit in the ones place of the second number. 

Step 2: 

We multiply the first number by the digit in the tens place of the second number. 

Step 3: 

We add the answers in Step 1 and Step 2.

 

 

Question 1: 

Solve the following multiplication. 

\(18 \times 12 =\) __________     

 

Solution:

Step 1: 

Step 2: 

Step 3:

Think about this! 

You can see \(12 = 10 + 2\)

\(\begin{align*}​ 18 \times 10 &= 180 \\ 18 \times 2 &= 36 \\ 180 + 36 &= 216 \end{align*}\)

Answer:

\(216\)

 

 

Question 2: 

Solve the following multiplication.

\(67 \times 38 =\) __________

 

Solution:

Answer:

\(2546\)

 

 

Question 3: 

Solve the following multiplication.

\(27 \times 31 =\) __________

 

Solution: 

Answer:

\(837\)

 

 

4. Multiplication Of 3-Digit By 2-Digit Numbers

The multiplication of \(3-\)digit numbers by \(2-\)digit numbers is similar to the multiplication of \(2-\)digit numbers by \(2-\)digit numbers.

 

Step 1: 

We multiply the first number by the digit in the ones place of the second number. 

Step 2: 

We multiply the first number by the digit in the tens place of the second number. 

Step 3: 

We add the answers in Step 1 and Step 2.

 

Question 1: 

Solve the following multiplication. 

\(132 \times 18 =\) __________

 

Solution:

Step 1: 

Step 2: 

Step 3:

Think about this! 

You can see, \(18 = 10 + 8\).

\(\begin{align*}​ 132 \times 10 &= 1320 \\ 132 \times 8 &= 1056 \\ 1320 + 1056 &= 2376 \end{align*}\)

Answer:

\(2376 \)

 

 

Question 2: 

Solve the following multiplication. 

\(413 \times 26 =\) __________

 

Solution:

Answer: 

\(10 \,738\)

 

 

Question 3: 

Solve the following multiplication. 

\(634 × 38=\) __________   

 

Solution:

Answer:

\(24 \,092\)


 

Continue Learning
Multiplication Whole Numbers
Multiplication And Division Decimals
Model Drawing Strategy Division
Fractions Factors And Multiples
Area And Perimeter 1 Line Graphs
Time  

 

Resources - Academic Topics
Primary
Primary 1
Primary 2
Primary 3
Primary 4
English
+ More
Maths
Multiplication
Whole Numbers
Line Graphs
Time
Multiplication And Division
Decimals
Model Drawing Strategy
Division
Fractions
Factors And Multiples
Area And Perimeter 1
+ More
Science
+ More
Primary 5
Primary 6
Secondary
Secondary 1
Secondary 2
Secondary 3
Secondary 4
+ More
Sign up for a free demo
(P1 to S4 levels)
Our Education Consultants will get in touch to offer a complimentary product demo and Strength Analysis to your child.
Ready to power up your
child's academic success?
Let our Education Consultants show you how.
*By submitting your phone number, we have your permission to contact
you regarding Geniebook. See our Privacy Policy.