They calculated percentages and figured out how much tax they would have to pay for items. But they didn’t limit their practice to numbers and equations: They collected money and shopped for three boys and three girls selected through the Angel Tree program who may not otherwise get holiday gifts this year.

Youngsters from the year-round Apex school recently took part in the field trip. The 120 or so sixth-graders got into groups and had to “plan buy” items that totaled less than $100, including tax.

They had one and a half hours, and a parent or teacher supervised their shopping. The six winning groups then went back and bought the items they selected.

Here, teachers Jason Dapkevich (science), Karla Mullen (math), Sarah Coulter (language arts) and Emily Swanson (social studies) talk about the experience.

Q: Have you done a field trip like this before? Were you able to teach lessons in different disciplines to prepare for the trip?

Karla Mullen: We have not done anything similar in the past. Another math teacher at Salem asked if we would be interested, and all of my teammates were excited. We thought we would only be able to shop for one boy and one girl, but we collected enough money that we were able to buy for six children.

Emily Swanson: In addition to the math, I was able to teach social skills as part of my social-behavior curriculum. A lot of our kids come from well-off families, so the process was an eye-opener for them.

KM: We did lessons ahead of time to calculate discounts, percentages and tax by searching online for gifts. Ms. Coulter gave them a map of the mall so that they had a plan of where they wanted to go. Each student was assigned a role: team leader, map reader, calculator, checker or timekeeper.

Q: Were there any surprises as you watched them search for gifts?

Jason Dapkevich: Students had to remind each other that the children they were buying for wouldn’t have the same luxuries that they have. Buying an Xbox game wasn’t an option.

My group passed a DVD store and found a rack of DVDs for $5. One student said, “We can’t assume they have a DVD player.”

I could see my students understanding the true meaning of the holidays and realizing that not all kids their age have the bells and whistles they do.

Sarah Coulter: By the end, we noticed that some of the groups struggled to meet the deadlines. We saw some frustration about not winning. We reminded those students that the focus is not about winning. We needed to remember the reason for the trip.

KM: One parent who has been on many field trips with her kids in the past wrote us to tell us thank you for including her. She said it was one of her favorite field trips ever. She was astounded by the good planning and message.

Q: Have you gotten other feedback about the field trip?

KM: Two of the three donations have already been picked up. The parents were floored, amazed and thankful. One said to me, “It couldn’t have come at a better time.”

JD: One of the best parts of the trip for me was when one group that did not get selected to go buy their items put together the money they brought for food and purchased a jacket they had found to give to their assigned child “just because.” Witnessing that made my heart melt.