Calculating Total Price With Tax
Calculating the total price with tax is a two-step process: first multiply the item price by the tax rate (as a decimal) to find the tax amount, then add that to the original price. For example, a $120 bike with 6% tax has a tax of 120 × 0.06 = $7.20, giving a total of $127.20. This practical 7th grade math skill from Saxon Math Course 2 appears in everyday shopping, budgeting, and financial literacy, making it one of the most immediately useful percent applications students learn.
Key Concepts
Property To find the total price, you must first calculate the sales tax and then add it to the initial price. The sales tax is found by calculating the given percent of the initial price.
Examples A bike costs $120$ dollars with a $6\%$ tax. Tax: $120 \times 0.06 = 7.20$ dollars. Total: $120 + 7.20 = 127.20$ dollars. An $18$ dollars book has a $5\%$ tax. Tax: $18 \times 0.05 = 0.90$ dollars. Total: $18 + 0.90 = 18.90$ dollars.
Explanation Don't let tax surprise you at the checkout! It's a simple two step process. First, multiply the item's price by the tax rate (as a decimal) to find the tax amount. Then, add that tax to the original price to get your final grand total. Every shopper needs this skill!
Common Questions
How do you calculate total price with sales tax?
Multiply the item price by the tax rate as a decimal to find the tax amount, then add it to the original price. For a $50 item with 8% tax: $50 × 0.08 = $4 tax, so the total is $54.
How do you convert a tax percent to a decimal?
Divide the percent by 100. For example, 6% becomes 0.06 and 8.5% becomes 0.085. Then multiply this decimal by the price to find the tax amount.
Can you calculate total price with tax in one step?
Yes. Add 1 to the tax rate decimal and multiply by the original price. For 6% tax: total = price × 1.06. This skips the separate tax calculation.
What grade learns about calculating price with tax?
Calculating total price with sales tax is a 7th grade skill covered in Saxon Math Course 2, Chapter 6, connecting percent operations to real-world financial math.
Why do different states have different tax rates?
Sales tax rates are set by state and local governments as a source of public revenue. They vary from 0% in states with no sales tax to over 10% in some localities.
What is a common mistake when calculating tax?
Forgetting to convert the percent to a decimal before multiplying. Using 6 instead of 0.06 gives a tax amount 100 times too large.