Mental Multiplication Strategies

Multiplication Tricks for Class 5 Math

Multiplication tricks are used to solve mathematical problems quickly. Here students will learn to use math multiplication tricks and mental math multiplication.
In this learning concept, the students will also learn to

• Classify the multiplication short tricks.
• Evaluate the problem by using multiplication short tricks and easy multiplication tricks.
• Identify the fast multiplication tricks and 11 multiplication tricks.

Each concept is explained to class 5 maths students using illustrations, examples, and mind maps. Students can assess their learning by solving the two printable worksheets given at the page’s end.

Download the multiplication tricks worksheet for class 5 and check the solutions to the multiplication tricks questions for class 5 provided in PDF format.

Mental Math Multiplication:

Let us learn some of the multiplication tricks:

Multiplication Short Trick for 4-Digit Numbers:

Let us consider two numbers as a b c d and e f g h.
Now, a b c d × e f g h

Step 1:(d × h)

Step 2:[ (c × h) + (d × g)] + add number if any carry over from previous step.

Step 3: [(b × h) + (c × g) + (d × f)] + add number if any carry over from previous step.

Step 4: [ (a × h) + (b × g) + (c × f) + (d × e)] + add number if any carry over from previous step.

Step 5: [ (a × g) + (b × f) + (c × e)] + add number if any carry over from previous step.

Step 6: [(a × f) + (b × e)] + add number if any carry over from previous step.

Step 7:(a × e) + add a number if any carry over from the previous step.

Example:
Find the product: 4532 × 3251

Step 1: 2 × 1 = 2. Take 2 for an answer (Ans: 2)

Step 2: [ (3 × 1) + (2 × 5)] = 3 + 10 = 13
Take 3 for an answer and 1 to be carried over to the next step. (Ans: 32)

Step 3: [ (5 × 1) + (3 × 5) + (2 × 2)] + 1 = 5 + 15 + 4 + 1 = 25
Take 5 for an answer and 2 to be carried over to the next step. (Ans: 532)

Step 4: [(4 × 1) + (5 × 5) + (3 × 2) + (2 × 3)] + 2 = 4 + 25 + 6 + 6 + 2 = 43
Take 3 for an answer and 4 to be carried over to the next step. (Ans: 3532)

Step 5:[ (4 × 5) + (3 × 3) + (5 × 2)] + 4 = 20 + 9 + 10 + 4 = 43
Take 3 for an answer and 4 to be carried over to the next step. (Ans: 33,532)

Step 6:[ (4 × 2) + (5 × 3)] + 4 = 8 + 15 + 4 = 27
Take 7 for an answer and 2 to be carried over to the next step. (Ans: 7,33,532)

Step 7:(4 × 3) + 2 =12 + 2 = 14
Therefore, the final answer is 1,47,33,532.

            Easy Multiplication Tricks of a Number by a Given Number Which Contains All the Digits a 9:

Step 1:Split the number which contains all the digits as 9 in the form of (multiple of 10 – 1).

Step 2: Now, we multiply (multiple of 10 – 1) by the other given number.

Step 3: Now, we simplify the arithmetic operations.

Example 1:

Multiply 230 by 9999.

Solution:

Step 1:9999 can be written as (1,00,000 – 1).
Hence, the given problem can be written as
230 × (1,00,000 – 1)

Step 2: Now,
230 × (1,00,000 – 1)
= (230 × 1,00,000) – (230 ×1)

Step 3: (230 × 1,00,000) – (230 ×1)
=23,000,000 – 230
=22,999,770
Therefore, the product of 230 and 9999 is 22,999,770.

Example 2:

Multiply 1352 by 99,999

Solution:

Step 1: 99,999 can be written as (1,000,000 – 1).
Hence, the given problem can be written as
1352 × (1,000,000 – 1)

Step 2: Now,
1352 × (1,000,000 – 1)
= (1352 × 1,000,000) – (1352 × 1)

Step 3: (1352 × 1,000,000) – (1352 ×1)
=1352,000,000 – 1352
=1,351,998,648
Therefore, the product of 1352 and 99,999 is 1,351,998,648.

                            11 Multiplication Tricks:

Rule: Add the digits to the digits on the right side.

Example 1:

Multiply 2541 by 11

Solution:

2541 × 11
(0+2) (2+5) (5+4) (4+1) (1+0)
2       7     9     5     1
2541 × 11 = 27951

Another method:

We can also do the multiplication by splitting 11 as (10 + 1)
Thus, 2541 × 11
= 2541 × (10 + 1)
= (2541 × 10) + (2541 × 1)
= 25,410 + 2541
=27,951
The answer in both methods is the same.

      Maths Multiplication Trick When a Number Is Multiplied by 12:

Rule: Starting the rightmost digit, then double each digit and add the digit on the right.

If the answer is greater than a single digit, simply carry over the extra digit to the next step. The remaining digit is ones digit of the final result.

Example:

Multiply 3453 by 12

Solution:

3453 × 12
Let us write the number 3453 as 03453
Rightmost digit 3 has no digit in the right
3 × 2 = 6
Next digit 5 has 3 in the right
5 × 2 + 3 = 10 + 3 = 1 3 (we take 3 and carry 1 in the nest step).
Next digit 4 has 5 in the right
4 × 2 + 5 + 1 = 8 + 5 + 1 = 1 4(we take 4 and carry 1 in the nest step).
Next digit 3 has 4 in the right
3 × 2 + 4 + 1 = 6 + 4 + 1 = 1 1 (we take 1 and carry 1 in the nest step).
Next digit 0 has 3 in the right
0 × 2 + 3 + 1 = 0 + 3 + 1 =4

So, the answer is 41,436.