Top

## Mental math often involves the use of specific techniques devised for specific types of problems.

 Related Calculators Addition and Subtraction of Polynomials Calculator Addition and Subtraction of Rational Expressions Calculator Addition Calculator Subtraction Calculator

Below are the examples on mental math addition

### Solved Examples

Question 1: Add 36 and 42.
Solution:
Step 1: Add the two ones' place digits: 6 + 2 = 8.

Step 2: Add the two tens' place digits: 3 + 4 = 7.

Step 3: The sum of the ones' place digits is less than 10.

Question 2: Add 84 and 49.
Solution:

Step 1: Add the two ones' place digits: 4 + 9 = 13.

Step 2: Add the two tens' place digits: 8 + 4 = 12.

Step 3: The sum of the ones' place digits is a two-digit number so decrease the ones' place sum by 10: 13 - 10 = 3 and

increase the tens' place sum by 1: 12 + 1 = 13.

Step 4: Combine the tens' and ones' place sums.

## Mental Math Subtraction

Below are the examples on mental math subtraction

### Solved Examples

Question 1: Subtract 26 from 75.
Solution:

Step 1: Subtract the two tens' place digits: 7 - 2 = 5

Step 2: Bottom one's digit is larger than the top one's digit.Decrease the answer for the tens' place by 1: 7 - 1 = 6 and

increase the top ones place value by 10: 5 + 10 = 15.

Step 3: Subtract the two ones' place values: 15 - 6 = 9

Step 4: Combine the tens' and ones' place value.

Question 2: Subtract 53 from 85.
Solution:

Step 1: Subtract the two tens' place digits: 8 - 5 = 3

Step 2: Subtract the two ones' place digits: 5 - 3 = 2

Step 3: Combine the tens' and ones' place value.

## Mental Math Multiplication

Below are the examples on mental math multiplication

### Solved Examples

Question 1: Multiply 35 by 6
Solution:
Step 1: Multiply the one's digit by 6, 6 x 5 = 30

Step 2: Multiply the ten's digit by 6, 6 x 3 = 18

Step 3: Product of one's place is two digit 30, so add the ten's digit into 18, 18 + 3 = 21

Step 4: Combine the one's and two's place value

Question 2: Multiply 56 by 4
Solution:
Step 1: Multiply the one's digit by 4, 6 x 4 = 24

Step 2: Multiply the ten's digit by 4, 5 x 4 = 20

Step 3: Product of one's place is two digit 24, so add the ten's digit into 20, 20 + 2 = 22

Step 4: Combine the one's and two's place value

## Mental Math Division

Below are the examples on mental math Division

### Solved Examples

Question 1: Divide 84 by 7
Solution:
Step 1: Divide the ten's digit by 7, $\frac{8}{7}$ = 1 with remainder 1

Step 2: Multiply 1 by 10, 1 x 10 = 10 and add it to one's place, 10 + 4 = 14

Step 3: Divide 14 by 7, $\frac{14}{7}$ = 2

Step 4: Combine the one's and two's place values

Question 2: Divide 96 by 6
Solution:
Step 1: Divide the ten's digit by 9, $\frac{9}{6}$ = 1 with remainder 3

Step 2: Multiply 3 by 10, 3 x 10 = 30 and add it to one's place, 30 + 6 = 36

Step 3: Divide 36 by 6, $\frac{36}{6}$ = 6

Step 4: Combine the one's and two's place values