Summary

Videos

References

**Multiplication of decimals**

**Steps to multiply a whole number by a decimal number:**

Step 1: Ignore the decimals and multiply the two numbers.

Step 2: Count the number of digits to the right of decimal point in the original decimal number.

Step 3: Insert the decimal in the answer by the same count from right to left.

e.g. (i) 3 Ã— 0.2 = 0.6 (ii) 3 Ã— 0.4 = 1.2

**Steps to multiply a decimal number by a decimal number:**

Step 1: Ignore the decimals and multiply the two numbers.

Step 2: Count the number of digits to the right of decimal point in both the decimal numbers

Step 3: Add the number of digits counted and insert the decimal in the answer by the same count from right to left.

e.g. (i) 0.2 Ã— 0.7 = 0.14 (ii) 0.9 Ã— 0.02 = 0.018

**Multiplication of a decimal number by 10, 100 or 1000:**

- For multiplying a decimal number by 10, retain the original number and shift the decimal to the right by one place
- For multiplying a decimal number by 100, retain the original number and shift the decimal to the right by two places
- For multiplying a decimal number by 1000, retain the original number and shift the decimal to the right by three places

**Division of decimals**

**Steps to divide a decimal number by a whole number:**

Step 1: Convert the decimal number into a fraction.

Step 2: Find the reciprocal of the divisor.

Step 3: Multiply the fraction by the reciprocal .

e.g. 0.14 Ã· 3 = $\frac{\text{14}}{\text{100}}$ Ã— $\frac{\text{1}}{\text{3}}$ = $\frac{\text{14}}{\text{300}}$

**Steps to divide a decimal number by another decimal number:**

Step 1: Convert both the decimal numbers into fractions.

Step 2: Find the reciprocal of the divisor.

Step 3: Multiply the fraction by the reciprocal.

e.g. 0.45 Ã· 0.15 = $\frac{\text{45}}{\text{100}}$ Ã· $\frac{\text{15}}{\text{100}}$= $\frac{\text{45}}{\text{100}}$Ã— $\frac{\text{100}}{\text{15}}$= 3

**Multiplication of decimals**

**Steps to multiply a whole number by a decimal number:**

Step 1: Ignore the decimals and multiply the two numbers.

Step 2: Count the number of digits to the right of decimal point in the original decimal number.

Step 3: Insert the decimal in the answer by the same count from right to left.

e.g. (i) 3 Ã— 0.2 = 0.6 (ii) 3 Ã— 0.4 = 1.2

**Steps to multiply a decimal number by a decimal number:**

Step 1: Ignore the decimals and multiply the two numbers.

Step 2: Count the number of digits to the right of decimal point in both the decimal numbers

Step 3: Add the number of digits counted and insert the decimal in the answer by the same count from right to left.

e.g. (i) 0.2 Ã— 0.7 = 0.14 (ii) 0.9 Ã— 0.02 = 0.018

**Multiplication of a decimal number by 10, 100 or 1000:**

- For multiplying a decimal number by 10, retain the original number and shift the decimal to the right by one place
- For multiplying a decimal number by 100, retain the original number and shift the decimal to the right by two places
- For multiplying a decimal number by 1000, retain the original number and shift the decimal to the right by three places

**Division of decimals**

**Steps to divide a decimal number by a whole number:**

Step 1: Convert the decimal number into a fraction.

Step 2: Find the reciprocal of the divisor.

Step 3: Multiply the fraction by the reciprocal .

e.g. 0.14 Ã· 3 = $\frac{\text{14}}{\text{100}}$ Ã— $\frac{\text{1}}{\text{3}}$ = $\frac{\text{14}}{\text{300}}$

**Steps to divide a decimal number by another decimal number:**

Step 1: Convert both the decimal numbers into fractions.

Step 2: Find the reciprocal of the divisor.

Step 3: Multiply the fraction by the reciprocal.

e.g. 0.45 Ã· 0.15 = $\frac{\text{45}}{\text{100}}$ Ã· $\frac{\text{15}}{\text{100}}$= $\frac{\text{45}}{\text{100}}$Ã— $\frac{\text{100}}{\text{15}}$= 3