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Plotting Potato Weights

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2.L.2.2 Recognize that there is variation among individuals that are related.

Lesson Summary

When to use this lesson This lesson is used during the potato harvest in September. Objective Students weigh harvested potatoes to create and analyze a line plot of the weights.


  • 1 garden fork for leader
  • 5 containers to store harvested potatoes
  • 5 buckets of water to rinse harvested potatoes
  • Towels for wiping potatoes
  • Trowels for students
  • Water key
  • Sample potato plant
  • Small food scale for each team of 5 students
  • Large food scale to weigh entire harvest
  • Worksheet for each student
  • Pencil for each student
  • Clipboard for each student
  • Toothpicks
  • Serving plate

Estimated Duration  30 minutes

Mathematics – Measurement and Data

Represent and interpret data.

  • 4.MD  Make a line plot to display a data set of measurements in fractions of a unit (1/2, ¼, 1/8). Solve problems involving addition and subtraction of fractions by using information presented in line plots.

  In Advance

  • Harvest locations are assigned and posted in the barn.
  • If needed, use a garden fork to loosen the soil in the potato location.
  • Set up 5 stations for teams of students. Each station has one bucket filled with water, one towel, one small food scale, and one empty container to store harvested potatoes.

Harvesting Potatoes

  • Today students are harvesting potatoes. Remind students that the potatoes we are harvesting were planted last spring. At the end of the activity, students will share in a tasting of potatoes.
  • Show the sample plant and point out how the potato develops. What plant part is a potato? A stem. The potato plant received food from the seed potato planted last spring, water from the roots, and food from the leaves. In the spring, a plant grew from the planted potato. In the summer, the potato plant grew flowers. At the end of the summer, the potato plant reached the end of its life cycle and died. That’s our signal to harvest.
  • Students will be weighing potatoes they harvest and recording the weights on a line plot. Show the worksheet and discuss the line plot.
  • What is a line plot? A line plot is a graph that shows frequency of data on a number line. We’ll be able to quickly see the mode, which is the weight that occurred the most; the range of all the weights, which is the lightest to the heaviest weight; the range where most of the weights are clustered or grouped; and outlier weights, which are weights that are very different from the cluster.
  • Discuss the worksheet. Each potato weight is plotted with an “x” – even if a potato of the same weight has already been recorded. We are trying to find the frequency of weights
  • Below is a sample of these potato weights:  6, 3, 3, 1, 11, 4, 4, 3, 7, 2. The mode is 3 ounces. The range is 1-11 ounces. The outlier is 11 ounces. There is a cluster from 1-4 ounces.

Weights of Harvested Potatoes

x x
x x x x x x x
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


  • Students work in teams of 5-6 students to harvest and weigh potatoes and to graph on a line plot the weights of the potatoes they harvest.
  • Explain that students use trowels to uncover the potatoes for harvesting. Model how to handle a trowel. Remove small amounts of soil at a time to avoid damaging tubers. Explain that the point of the trowel is always down and that tool should be stuck in the ground with the handle pointing up when it is not being used or until the trowel is returned to the storage container.
  • Potatoes that are smaller than a cherry tomato should be buried back in the ground. Show an example of the size. They’ll grow early next spring.
  • Each team of students works in close proximity to each other to harvest potatoes. When 10 potatoes have been harvested by the team, they take their harvested potatoes to their team’s weighing and washing station. The holes from harvesting should be filled and the trowels returned to the storage container.
  • Students take turns weighing potatoes. Potato weights are rounded to the nearest whole ounce. Each weighed potato is placed into the bucket of water. Students plot each potato weight on their graph. After each potato has been weighed, the potatoes in the water are rinsed and stored.
  • Towels are provided to gently wipe, but not scrub, the potatoes so the thin skin stays on the potatoes. Potatoes should be handled gently. Potatoes should not be dropped into containers because they will bruise easily and become rotten from the bruise.
  • Discuss the questions at the bottom of the worksheet to share information about the potatoes harvested by each team.
  • If you have time, weigh the total class harvest on a large food scale.

Leave time to sample prepared potatoes

  • A cooler of prepared potatoes to sample will be in your garden area. Collect one bag for your class.Use the plate to serve students.
  • Keep the sampling hygienic by having students sample foods using toothpicks.

Clean up

  • The last person to use the cooler each day returns the cooler to Granny’s office.
  • Deliver the harvest to trays on the tables outside Granny’s office.
  • Clean and dry your serving plate and buckets, and return them to the barn.
  • Hang towels outside to dry.

Potato trivia if you have time

  • At the start of your lesson or during the tasting at the end, you may have time to discuss some of the following information.
  • In the US, more potatoes are eaten than any other vegetable – more than twice the amount of the next most popular vegetable, the tomato.
  • Potatoes are grown in all 50 states and in many countries around the world.
  • There are thousands of different varieties of potatoes worldwide. Our gardens are planted with about 4 different kinds of potatoes.

Potato eyes are the buds that grow from dimples, small indentations, on the potato. The eyes are the new plant. The dimple makes up the eyebrow.

  • The small specks on the surface of potatoes are called lenticels (len’-tuh-sel) and allow the potato to “breathe”. Too wet soil near harvest time can cause lenticels to swell. These do not affect the eating quality of potatoes unless bacteria enter and cause rotting. Rotting lenticels appear as circular, sunken, brownish spots.
  • All parts of the potato plant except the tuber are toxic if eaten.
  • The largest potato on record was grown in England in 1795 and weighed 8 pounds, 4 ounces, according to the Guinness Book of World Records.
  • In 1974, Eric Jenkins, an Englishman, grew 370 pounds of potatoes from one plant.
  •  If you find a potato with greenish skin, the potato was exposed to the sun. The green is chlorophyll that is starting to form in the skin. Along with the chlorophyll, a mild, bitter toxin, called solanine, becomes more concentrated.
  •  Potatoes are 80% water and 20% solid.
  •  65% of potatoes are made into potato chips and boxed and frozen potato products.
  •  Tomato and potato plants are similar in appearance and are related.
  •  Cooking French fries originated in Europe (France or maybe even Belgium) but did not become widely accepted in America until introduced by Thomas Jefferson at a White House dinner during his presidency from 1801 to 1809.
  •  Potato chips originated in the United States in 1852, when Chef George Crum fried a thin crispy chip after a customer at his restaurant complained the French fries were too thick. This happened in Saratoga, New York. The chips were called Saratoga Chips.
  •  During the Alaskan Klondike gold rush, miners traded gold for potatoes because of the vitamin C content.

Potatoes are a good source of:

Vitamins are organic and come from plants and animals. Benefits
Vitamin C
  • Keeps your muscles, teeth, and gums healthy
  • Helps cuts to heal
  • Helps your body to fight infection when you are sick
Vitamin B6
  • Helps you make and release energy
  • Helps make red blood cells that carry oxygen to your body parts
Minerals are inorganic and come from soil and water. Benefits
  • Helps muscle coordination
  • Helps nervous system functioning
  • Helps balance the right amount of water in blood and body tissue

From KidsHealth.com, http://kidshealth.org/kid/stay_healthy/food/vitamin.html?tracking=K_RelatedArticle#cat119 and http://kidshealth.org/kid/stay_healthy/food/minerals.html?tracking=K_RelatedArticle#cat119, 07-04-11.


  • Terrific Taters:  Nutrition Ideas for Schools and Families. The National Potato Promotion Board.
  • The Amazing Potato by Milton Meltzer. Harper Collins Publisher:  New York, New York, 1992.
  • Fun Fact and Trivia, Washington State Potato Commission,
  • The Origin of Potatoes, Idaho Potatoes,
  • The Hot Potato- Potato Facts,
  • Nutrition Facts, Idaho Potato Commission, .
  • Inspection Section:  Enlarged Lenticels in Potatoes, Department of Agriculture Activities, Alaska Department of Natural Resources, Newsletter, September 28, 2009,
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