Math on the Farm


"We use math every minute on the farm!"

While Farmer might not be on the top of the list for STEM jobs, maybe it should be! Most children, even very young children, can connect to farms. From singing songs to the foods on the dinner plate, children are already interested. We can build on that interest to show our children real-world math. 

Imagine a profession where math is used every minute of every workday. There’s engineering, accounting or even teaching math. Oh, and don’t forget farming. This month we’re sharing some real-world math problems that our friends at the farm tackle every day.

Jack and Beckie Gurley run the USDA certified organic Calvert Gift Farm in Sparks, MD and have since 1994. My family joined their CSA 5 years ago when we moved to the area. We just love it. They grow a variety of produce depending on the season and weather. Each week our share contains around eight items such as kale, romaine, arugula, berries, squash, sunchokes, garlic scapes, potatoes, tomatoes, shiitake mushrooms, beets, and eggplant (Full List Here).

We reached out to the Gurley’s to find out how is math used to produce crops and run operations on a farm? The answer was simple: “We use math every minute on the farm,” said Beckie.

“Tell me more!” I asked. Beckie laughed and shared with us a few of the many challenges that the team confronts and solves.

Most of the plants begin as “transplants,” meaning the seeds go into "cell trays" with potting mix, germinate in the trays, and then are planted in the field. The cell trays are all the same size, 12 inches x 24 inches", but the actual number of cells per tray can vary from 72 (1 inch squares) to 225 (¼ inch squares). The transplant trays stay in the greenhouse until they germinate and then go out into the field. The greenhouse has 4 benches, each 30 feet x 40 feet to hold the trays.

We’ve counted at least a few math problems to work out in this planning scenario!

Whether the task is planning, planting, harvesting or selling, each year, season, week or day, the Gurley’s are math explorers and problem solvers, and spend a lot of time answering these questions:

  • What day should we start if we want to harvest on a certain day?

  • How many plants should we buy for a particular space?

  • How much money should I charge for our crops at the market?

  • How much space will our “cell trays” take up in the greenhouse?

  • What are some variables that could impact our schedule or amounts?

These questions are usually asked as part of a larger schema, like in these real-world farming examples from Beckie:

“Jack wants to grow 2,000 onion plants, he likes the 225 cell trays.  How many trays do we need to seed? If we want to have an 8 week old transplant to put out in the field on April 1, what day should he start the trays? How much space will those trays take up in the greenhouse?”

“We want to do 3 plantings of tomatoes. The first planting goes into the high tunnel, which can fit 3 rows that are each 50 feet. If the plants are placed 2.5 ft apart, how many plants should we start? Those plants get transplanted on April 23rd. If we put out a 6 week transplant, when should they get started? The next planting goes out on May 5. We have 3 rows that are each 225 feet. How many plants, when to start? We do the same exercise on June 1st.”

“We want more blackberry plants. How many seedling plants should we buy if the row is 225 feet long and the plants are placed 3 feet apart?”

“How much space do I need for garlic? Jack has ordered 180 lbs of seed garlic. Each pound has approximately 10 fists of garlic [Beckie estimated by weighing 3 lbs, counted the number of fists and divided by 3]. Each fist has approximately 6 cloves. Each clove is planted 6 inches apart. How many row feet will we need? If the rows are 225 ft long and 2 ft apart, how big will the entire bed be?”

“I am at the market and I have put 5 onions into a box to sell for $3.50. A customer only wants one onion. How much should I charge?”

“We have 23 CSA customers that pick up on Tuesdays. If they each get 1.5 lbs of potatoes, how many potatoes does Jack need to dig? How many bags does Taylor need to weigh out and fill? How much will it cost for some of us to get manicures because now our nails are filthy!”  

Neither Jack or Beckie grew up on a farm, but according to Beckie, they each “envisioned some kind of farm life” for their future. These two attribute at least some of their success to the fact that they “didn’t have any prior knowledge of ‘how things should be done.’ We have been able to make  lot of things up as we go along!”

#mathexplorers #happyplaying #practicalmath #calvertgiftfarm