How to Multiply Decimals by Whole Numbers
Multiplying decimals by whole numbers is a straightforward process. Here’s a step-by-step guide to help you:
Step 1: Ignore the Decimal Point
- Temporarily treat the decimal number as a whole number by ignoring the decimal point.
- For example, if you want to multiply 3.25 by 4, think of 3.25 as 325.
Step 2: Multiply as Whole Numbers
- Multiply the number you got (ignoring the decimal) by the whole number.
- Using the example: 325 × 4 = 1300.
Step 3: Count the Decimal Places
- Count how many digits are to the right of the decimal point in the original decimal number.
- In 3.25, there are 2 digits after the decimal.
Step 4: Place the Decimal Point
- Starting from the right of your product (1300), move the decimal point to the left by the number of decimal places you counted.
- Move the decimal 2 places to the left: 1300 → 13.00.
Step 5: Write the Final Answer
- The final answer is 13.00, which is simply 13.
Example 2:
Multiply 0.6 by 7.
- Ignore the decimal: 0.6 → 6
- Multiply: 6 × 7 = 42
- Decimal places in 0.6 = 1
- Move decimal point 1 place left: 42 → 4.2
- Final answer: 4.2
Quick Tips:
- Multiplying by a whole number does not change the number of decimal places.
- Always count decimal places in the original decimal number before multiplying.
- Practice with different decimals to get comfortable!
If you want, I can provide practice problems or more examples!
