Answering Math Questions at Retail Job Interviews

Retail Clerk Gives Change to Customer
••• Jeff Greenberg / Getty Images

Doing math on the spot makes many people flustered. But if you work in retail, interviewers may want to confirm you have a basic grasp of addition and subtraction. After all, it's always possible the power will go out and you'll won't be able to rely on your cash register! 

Here's what you need to answer math questions at a retail job interview with confidence. 

What the Interviewer Really Wants to Know 

When you're asked math questions during a retail job interview, the interviewer wants to know that you have basic math skills. 

Even though the cash register may automatically calculate the change for you, there are still moments when you'll need to do mental math. For instance, customers may have questions about discounts that you'll need to answer on the fly. Plus, at the end of a shift, you may need to count out the register, so basic math skills are important even with technology available to help. 

Common Math Questions at Retail Job Interviews

Knowing how to figure out the correct change and estimate discounts and tax when a customer purchases merchandise is a key skill for retail workers. Here are some common types of math-related question you might get during a retail interview—and strategies for working out the mathand your response. 

How Do You Count Out Change? 

When you are making the change for a cash purchase, even if the cash register does the math for you, always count the change back to the customer.

  • Example: The customer makes $23.78 in purchases, and gives you $30.00. You count back to the customer: "22 cents makes 24 dollars, 1 dollar makes $25, and 5 makes $30."
  • Example: The customer makes $11.56 in purchases, and gives you $15.06. You count back to the customer: "50 cents makes $12.06, 1,2,3 dollars make $15.06."

If an interviewer asks how you count out change to the customer, share the above strategy. It's not required to verbally count out the change — you can do it in your head. You will make fewer mistakes this way. 

In your response to your interviewer, you can mention if you opt to count aloud or in your head. 

How Do You Make Change? 

If you're asked about keeping cash in the register and what bills to use for making change, explain that you understand that it’s important to make sure your register is well stocked.

Retail establishments always set a base amount of money they need to keep in a cash register (typically $200) but it can vary based on a retailer's average daily sales. It’s important to keep adequate amounts of the most commonly used bills (1-dollar and 20-dollar bills) on hand. Whenever possible, you should also make change using bills of the highest denomination so that you don’t exhaust your supply of 1-dollar bills.

When making change, it's best to use the largest denomination bill you can. Less counting is less opportunity for mistakes in counting (or having bills stick together).

How Do You Calculate Discounts and Tax? 

You may be asked about calculating discounts for a customer. To give an easy, quick estimate of a percentage off, figure 10%, and multiply by the tens. 

  • Example: A customer wants to know the price of an item that is regularly $39.99, and it's 30% off. Round up to $40.00, 10% would be $4.00, times 3 would be 30% and $12.00 off. $40-$12 is $28.
  • Example: The regular price of an item is $70, and it's 25% off. 10% is $7.00, times 2 is $14, plus half of 10% is 5%, or $3.50. 25% is $14+$3.50=$17.50. $70-$17.50 is $52.50. Another way to look at 25% is to call it 1/2 of 50%. 50% of $70 is $35, so 25% is $35 divided by 2, or $17.50. $70-$17.50 is $52.50.
  • Example: An item costs $140, and the tax rate is 8.25%. 5% would be $7.00, plus (a little more than half again ~3%) approximately $4.00 is $11.00. $140+$11 = $151.00 for the approximate total cost of the item, tax included.

This may not be an exact number, depending on the change, but it's close enough to give a good estimate.

As with the other questions, you can always talk through your strategy while sharing your response. 

Tax can be estimated in the same way. Go with 5% and 10%, and you can get a number close enough to help a customer decide if they want the item.

Again, the actual cost may be a little different, but your estimate is able to help the customer make a more informed decision about their purchase.

Why Is It Important to Be Comfortable With Mental Math? 

Some interviewers may ask you if you think it's important to be able to do mental math. It may feel tempting to say no, since you likely have a calculator app on your phone. But when you're ringing up a customer's order on the till, you can't take out your phone—it would be rude and unprofessional.
Plus, making simple calculations in your head when you are checking out customers will help you to catch silly mistakes that can be avoided. For instance, if you know that the purchase is that $70 item at 25% off, and your register reads $27.32 as an amount due, you're going to know that something went haywire, and you can fix it before the customer leaves the store.

Paying attention to the details is what makes a superior sales associate and that's what interviewers are looking for when they ask math questions during a job interview. They not only want to be sure you can do the math, but they also want to make sure that you can estimate pricing, if necessary.

If you're asked about the importance of mental math for retail workers, explain that you know it'll help you catch—and avoid—errors.