Classroom activity Kindergarten Engineering & Design
Spoon or Straw: Two Watering Tools for the Bean Cups
A 30-minute kindergarten activity where groups test a spoon against a straw dropper on matching bean cups and choose the tool that waters without spilling.
Objectives
- Students will state the problem of watering a seed without soaking the table.
- Students will water two matching bean cups with two different tools.
- Students will compare the two wet mats and choose the tool that spilled less.
Vocabulary
Key words: tool, spill, seed, dropper
Teacher overview
Bean cups on a classroom windowsill are often watered straight from a pitcher, which floods the soil, wets the sill, and can rot the seed. This activity hands groups two tools instead of a pitcher and asks them to find out which one puts water on the soil and nowhere else.
The two tools behave differently for a reason students can see. A spoon carries a wide, shallow load that tips over the rim easily, while a straw held with a finger over the top releases a narrow column exactly where the finger lets go. Groups run both tools on matching cups over paper mats, and the traced wet rings are the test data they compare.
Introduce the straw dropper by demonstrating it once with the whole class watching. Dip, cover the top with one finger, lift, move over the soil, and lift the finger. Most kindergartners need two or three tries before the water stays in the straw, so allow practice over the bowl before the real test.
Activity Directions
- Before class, plant two bean seeds per group in clear cups of soil so that the pairs match. Set each cup on its own paper mat.
- Show the whole class the problem. Pour water from a pitcher into one spare bean cup until it overflows and puddles on the mat. Ask what went wrong, then build one class sentence and say it twice together: the seed needs a little water in its cup, and we want the table to stay dry.
- Put students in groups of three or four. Give each group two matching bean cups on mats, a teaspoon, a wide straw, and a small bowl of water.
- Demonstrate the straw dropper once at the front. Dip the straw, cover the top with one finger, lift it out, hold it over the soil, and lift the finger. Let every group practice over their bowl until the water stays in.
- Round one. One student waters the first bean cup using only the spoon, taking three spoonfuls. The rest of the group watches the mat.
- Round two. A different student waters the second bean cup using only the straw dropper, taking three straw loads. The group watches that mat.
- Groups trace the edge of any wet spot on each mat with a crayon, then hold the two mats side by side and point to the smaller ring.
- End the testing after about 20 minutes, once every group has traced both mats. Gather with two mats held up at the front and work through the three debrief questions on the group page.
Student Handout
Read each question aloud during the debrief. Groups answer together.
- Which tool left the smaller wet ring on the mat, the spoon or the straw?
- Why does spilled water on the table do nothing for the seed?
- Your group waters the class beans every day this week. Which tool will you pick, and what is your reason?
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: The straw dropper. Accept the tool each group actually observed as leaving the smaller ring, with a reason attached. The straw releases a narrow stream straight down, while a spoon spreads and tips.
- Answer: The roots are down in the soil, so water on the table never reaches them. Accept any answer saying the plant cannot drink water that is not in its cup.
- Answer: The straw dropper, because it puts water on the soil and keeps the sill dry. Accept either tool when the group gives a reason tied to what they saw on their own mats, such as a spoon being easier for small hands to control.
Differentiation
Support (below grade level)
Give these students a straw cut short, about the length of a finger, which is far easier to seal and lift. Let them practice over the bowl for as long as they need before joining the real round, and have them answer the debrief by pointing at the mat with the smaller ring.
Extension (above grade level)
Ask these groups to design a third tool from a folded index card or a plastic lid, predict whether its ring will be larger or smaller than the straw's, and test it on a third bean cup. Have them explain what part of their tool controls where the water lands.
ELL supports
Pre-teach spill, drop, soil, and dry with the class performing each one as a motion, such as fingers falling to show drops. Use the two traced mats as the answer to the first debrief question so language is not required, and accept a reason given in the home language with one English word added while you scribe.
Extensions
Keep the bean cups going for two weeks with the winning tool and have students report at morning meeting whether the sill stayed dry. Farms and orchards face the same problem at a far larger size and answer it with drip irrigation, which runs a thin tube along each row and lets water out slowly at every plant instead of spraying the whole field. Ask a school groundskeeper or a family member who gardens to show the class the tool they use for seedlings and to say in one sentence why they chose it.