National Agricultural Literacy Curriculum Matrix
Customary & Metric Food Measurement
3 - 5
Two 60-minute sessions
Students will use food and farming as a basis for exploring the concepts of estimating and measuring using customary and metric units of measurements.
Activity 1: Produce Shopping
- Variety of produce (apples, onions, potatoes, carrots, oranges, etc.)
- Grocery flyers listing prices for the produce, 1 per station
- Scales to weigh produce, 1 per station
- Produce Shopping activity sheet, 1 per student
- Customary and Metric Unit Equivalents Guide
Activity 2: Weight and Capacity Shopping
- 1 empty gallon jug
- 2 empty liter containers
- 2 empty quart containers
- 1 empty pint container
- 4 liquid measuring cups (measuring lines below the rims) with both customary and metric measurements
- 1 dry measuring cup
- Bag of unpopped "old fashioned" popcorn (not microwave)
- Box of cereal
- 3 buckets of water
- Teaspoon of salt
- Tablespoon of cinnamon
- Glass of milk
- Weight and Capacity Shopping activity sheet, 1 per student
Essential Files (maps, charts, pictures, or documents)
- Customary and Metric Unit Equivalents Guide
- Produce Shopping Activity Sheet
- Weight and Capacity Shopping Activity Sheet
bushel (bu): a unit for measuring an amount of fruit or grain equal to about 35.2 liters in the U.S. Variations in weight per unit of volume will vary in measuring a bushel due to the size of the commodity, condition and tightness in which it is packed, and degree to which the container is heaped such as a bushel of apples weighs approximately 40 lbs. however a bushel of harvested wheat weighs 60 lbs.
customary: a system of measurement used in the United States that includes units for measuring length, capacity, and weight
estimation: a rough calculation of the value, number, quantity, or extent of something
gallon (gal): a unit of volume for liquid measure equal to four quarts
gram (g): a metric unit of mass equal to one thousandth of a kilogram (kg)
liter (L): metric unit for measuring liquid volume, equal to 1000 milliliters (ml)
measurement: the size, length, or amount of something while using a customary unit for measuring
metric: a system of measurement based on multiples of ten that is used throughout the world
pint (pt): a unit of liquid or dry capacity equal to one half of a quart
pound (lb): the customary unit of measurement for weight, equal to 16 ounces (oz)
volume: amount of space an object occupies measured in cubic units
weight: a measurement indicating how heavy something is
Did you know? (Ag Facts)
- Farmers use math every day from basic measurements and calculations of geometry, proportions, multiplication, and division to more advanced math used in calibrating machinery and irrigation pumps.
- In the 1700s, over 500 units of measurements were used for length, weight, and volume.1
- In the 1850s, the first machine-made rulers were created. The standard ruler was 24 inches long and could be carried in a farmer's pocket when folded.1
- The old saying, "I wouldn't touch it with a 10 foot pole" came from the days before farmers had accurate measuring tools for building their barns. Farmers would use a 10 foot pole for building these structures.1
Background Agricultural Connections
Interest Approach – Engagement
- Fill a glass jar with blueberries. Count the number of blueberries as you place them in the jar and do not reveal this number to your students.
- Show the students the jar and have them estimate the number of blueberries. Take several guesses from the class.
- Next, pour water into the jar and allow it to fill to the top. Have the students examine the jar more closely and make a second estimation of the number of blueberries. Did their original estimation change? Why or why not?
- Ask the following questions:
- "Why do we estimate measurements?" (estimation gives us an approximate idea of something's weight, volume, length, or mass)
- "What kinds of estimations would a blueberry farmer use?" (pounds of blueberries harvested, inches of rain, etc.)
- "What other things can we estimate in the real world?" (length of a wall, distance to walk to a friend's house, weight of a backpack full of books, amount of time needed to finish homework, etc.)
- "Why is estimation an important skill?" (it is a tool for making quick judgments when it isn't necessary or practical to calculate an exact answer or make an exact measurement. Example: When grocery shopping, items placed in the basket are added up to make sure enough money is available to make the purchase.)
- "Why is estimation an important skill for a farmer?" (estimating yields of a crop for calculating profit, time to harvest a crop for the best rate of production, estimating pounds of feed for the most efficient weight gain in livestock animals)
- "How can estimations help make accurate measurements?" (estimations can help judge if the actual measurement is reasonable and accurate)
- Tell the students they will be making estimates and taking measurements using food items that farmers produce for us to enjoy as part of a nutritious diet.
Activity 1: Produce Shopping
- Set up four or five work stations, supplying each with a different kind of produce, a grocery flyer showing prices for each kind of produce, and a small scale that registers ounces and pounds (diet scales or kitchen scales).
- Divide the class into four or five groups, and assign each group to a work station. Hand out the Produce Shopping activity sheet, one per student.
- Review estimating, and discuss why it might be useful in a trip to the grocery store. Share the information found in the Background Agricultural Connections section of the lesson with the students.
- First, ask students to estimate the weight and cost of the produce and record their estimates on the activity sheet.
- Next, have them weigh the produce and calculate the cost based on the prices listed in the grocery flyers. If you have metric scales, record these weights or make the conversion with the students. A Customary and Metric Unit Equivalents Guide is provided in the Essential Files for making conversions.
- Ask the groups to move from station to station until each student group has visited each station.
- Students should complete the totals on the activity sheet.
- If all the totals are not the same, ask students to discuss possible reasons for the discrepancy (weights and costs may have been rounded up or down).
- For each type of produce ask student groups to research how US farmers measure the yield of the products per acre in at least one work station and share with the other student groups. For example, farmers measure the number of bushels of harvested wheat per acre.
Activity 2: Measurement Shopping
- Set up five work stations, and supply each with the following:
- Station 1: gallon jug, quart container, liter container, liquid measuring cup, and a bucket of water
- Station 2: quart container, liter container, pint container, liquid measuring cup, and bucket of water
- Station 3: box of cereal, popcorn, scale (discuss how to use the type of scale you have provided) and liquid measuring cup
- Station 4: 2 measuring cups, 1 liquid and 1 dry, and unpopped popcorn (more than 1 cup)
- Estimation Station 5: Measure and pour out onto a piece of paper: 1 cup of unpopped popcorn, 1 cup of cereal, 1 teaspoon of salt, and 1 tablespoon of cinnamon. Add a glass of milk to this estimation station; note how much milk you put in the glass to share with the students after they've made their estimates.
- Divide the class into five groups, and assign each group to a work station. Hand out the Weight and Capacity Shopping Activity Sheets, one per student.
- Instruct students to use the activity sheets to record their findings.
- Ask the groups to move from station to station until each group has visited each station.
- After all the groups have finished, discuss the following questions as a class:(answers will vary)
- "What did you learn about volume and weight?"
- "Are the two related?"
- "How difficult was it to measure accurately? How difficult was it to estimate accurately?"
- "Why is estimation an important skill?"
- "Why is it important to measure accurately?"
- "How are farmers from the US able to sell or discuss yields with farmers from other countries?"
Concept Elaboration and Evaluation:
After conducting these activities, review and summarize the following key concepts:
- Making accurate estimations and measurements are two important elements farmers use to effectively utilize their time, calculate yields, and manage their money.
- Customary and metric units of measurements are used for planting, harvesting, processing, packaging, and selling food items grown by farmers.
- Food items are measured and sold in various ways according to its purpose at the time of purchase.
We welcome your feedback! Please take a minute to tell us how to make this lesson better or to give us a few gold stars!
Visit a grocery store and find five products sold by the pound, five sold by the piece, and five sold according to volume.
Discuss the difference between weight and volume. Have students discuss whether it is more economical to buy produce by the pound, by the piece or according to volume. Why is produce usually sold by volume or by the piece in farmer's markets but by the pound in grocery stores?
Discuss various things that humans measure. (e.g. daily temperatures, amount of precipitation, air quality, body weight, and crop yields).
Suggested Companion Resources
- Fun with Almond Math (Activity)
- How Many Hats Does a Farmer Wear? (Activity)
- Math in the Garden (Teacher Reference)
Agricultural Literacy Outcomes
Culture, Society, Economy & Geography
- Describe how supply and demand impact the price of agricultural goods (T5.3-5.a)
Food, Health, and Lifestyle
- Explain the costs associated with producing and purchasing food. (T3.3-5.d)
- Identify food sources of required food nutrients (T3.3-5.g)
Science, Technology, Engineering & Math
- Describe how technology helps farmers/ranchers increase their outputs (crop and livestock yields) with fewer inputs (less water, fertilizer, and land) while using the same amount of space (T4.3-5.b)
- Provide examples of science being applied in farming for food, clothing, and shelter products (T4.3-5.d)
Education Content Standards
Economics Standard 8: Role of Prices
ObjectivePredict how changes in factors such as consumers' tastes or producers' technology affect prices.
Common Core Connections
Mathematics: Practice Standards
CCSS.MATH.PRACTICE.MP4Model with mathematics. Students can apply the mathematics they know to solve problems arising in everyday life, society, and the workplace. Students who can apply what they know are comfortable making assumptions and approximations to simplify a complicated situation, realizing that these may need revision later. They are able to identify important quantities in a practical situation and map their relationships using such tools as diagrams, two-way tables, graphs, flowcharts and formulas. They can analyze those relationships mathematically to draw conclusions.
CCSS.MATH.PRACTICE.MP6Attend to precision. Students try to communicate precisely to others. They try to use clear definitions in discussion with others and in their own reasoning. They state the meaning of the symbols they choose, including using the equal sign consistently and appropriately. They are careful about specifying units of measure, and labeling axes to clarify the correspondence with quantities in a problem. They calculate accurately and efficiently, express numerical answers with a degree of precision appropriate for the problem context.