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Two Buckets Puzzle

Most likely, you’ve ran across some variation of the two buckets puzzle at some time in your life. You have two buckets. One bucket holds exactly five gallons. The other bucket holds exactly three gallons. How can you measure exactly four gallons of water into the five gallon bucket?

Groupwork Norms for the Two Buckets Puzzle

When I taught physical science, I used this during the first week of school to give my students practice with problem solving while practicing some of our groupwork norms:

  • Give reasons for your suggestions.
  • Confusion is part of learning.

You can read more about these groupwork norm posters and download a set for your own classroom. Other tasks for practicing groupwork norms include Broken Circles, Rainbow Logic, and Guess My Rule.

Two Buckets Task Card

I created a task card for my students outlining the two buckets puzzle.

Two Buckets Puzzle Task Card

Students really struggled with the precision necessary in solving this puzzle. I had to continually circulate the room and remind students that eyeballing half of the bucket was not an acceptable problem solving strategy.

Students were challenged to work together to produce posters describing their solution process to the two buckets puzzle with words and illustrations

Student Work

Two Buckets Puzzle - Poster of Student Work
Two Buckets Puzzle - Poster of Student Work
Two Buckets Puzzle - Poster of Student Work

Reflection Form

After groups finished their posters, they completed a group reflection sheet to get them thinking carefully about the groupwork norms we were intentionally practicing.

Two Buckets Puzzle Reflection Sheet

Puzzle Solutions

I intentionally do not share solutions to the puzzles I feature on my website because I strive to provide learning experiences for my students that are not google-able. I would like other teachers to be able to use these puzzles in their classrooms as well without the solutions being easily found on the Internet.

However, I do recognize that us teachers are busy people and sometimes need to quickly reference an answer key to see if a student has solved a puzzle correctly or to see if they have interpreted the instructions properly.

If you are a teacher who is using these puzzles in your classroom, please send me an email at with information about what you teach and where you teach. I will be happy to forward an answer key to you.

Myrna Matulevich

Wednesday 18th of August 2021

Search Die Hard Jugs Problem on youtube for a video intro to this puzzle

Sarah Carter

Friday 20th of August 2021

Great suggestion!