Multiplying money
Multiplying money works just like multiplying whole numbers, with one critical final step: place the decimal point two positions from the right in the answer to separate dollars from cents. To find the cost of 3 tickets at $3.75 each, multiply 375 × 3 = 1125, then insert the decimal to get $11.25. This technique is taught in Saxon Math Intermediate 4 and is a foundational 4th grade math skill that connects arithmetic to everyday financial literacy, from shopping to budgeting.
Key Concepts
Property Multiplying money, like an amount in dollars and cents, is almost identical to multiplying whole numbers. The key difference is that you must place a decimal point two places from the right in your final answer. This correctly separates the dollars from the cents, ensuring the value is accurate for currency calculations.
Example Example 1: To find the cost of 3 tickets at 3.75 dollars each, you calculate $375 \times 3 = 1125$. Then, place the decimal two spots from the right. The total cost is 11.25 dollars. Example 2: For 5 items at 4.25 dollars each, you calculate $425 \times 5 = 2125$. Placing the decimal point two places from the right gives you a total cost of 21.25 dollars.
Explanation Multiplying money is just regular multiplication in a fancy suit! Calculate the product as if there were no decimal point. Once you have your total, place the decimal point two spots from the right. This magical dot transforms your pile of digits back into proper dollars and cents, ready for spending.
Common Questions
How do you multiply money amounts?
Ignore the decimal point and multiply the digits as whole numbers. Count the total decimal places in the original number (always 2 for money), then place the decimal point that many places from the right in the answer. For 4 × $2.50: 4 × 250 = 1000, then place the decimal: $10.00.
Where do you put the decimal point when multiplying money?
Always place the decimal point two places from the right of the final product, since money is expressed in dollars and cents with two decimal places.
What is a common mistake when multiplying money?
The most common error is forgetting to insert the decimal point, turning $11.25 into $1125. Always count two places from the right of the product and insert the decimal before writing the dollar sign.
When do students learn to multiply money?
Multiplying money amounts is a 4th grade math skill. Saxon Math Intermediate 4 introduces it as an extension of multi-digit multiplication with a real-world application in financial contexts.
How is multiplying money similar to multiplying decimals?
Multiplying money is identical to multiplying a decimal number with exactly two decimal places. The strategy of multiplying as whole numbers then placing the decimal applies to both.
How do you find the total cost of multiple items with the same price?
Multiply the price of one item by the number of items. For example, 5 notebooks at $1.25 each: 5 × 125 = 625, then place the decimal to get $6.25 total.