After I do the Gummy Bear Demo to pique their interest, I have found that this Mystery Solutions Puzzle is a great way to grab my students by their brains! I have used Flinn Scientific’s Mystery Solutions Activity for a few years, but this year my co-teacher and I gave it a digital facelift. The prep takes about 40 minutes and the materials are fairly easy to get.

I am providing a **FREE DOWNLOAD** of this resource in both the printable and digital versions plus a presentation with the overview of the activity to show to students, so be sure to scroll to the bottom to grab the freebie!

## Pairs of Students Solve a Puzzle While Working 500 Miles Apart

For this activity, you will make pairs of clear mystery solutions and label one set with letters (A, B, C, etc) and the other set with numbers (1, 2, 3, etc.). The solutions will be held in pipette bulbs and stored in cassette cases (and if you’re a child of the 80’s, it’s really funny seeing youngsters confused as to how to open these!!).

The point of this activity is that pairs of students imagine that they are working in laboratories 500 miles apart from one another and they have a puzzle to solve. They must figure out which lettered solution is the same as which numbered solution, but the pairs cannot see each other, they cannot talk, and they can only communicate by writing.

## Making It Digital

The first year that I did this activity, I put half of a cardboard box in between the partners so that they could work in their ‘laboratory’ without seeing their partner. They could communicate by writing on a piece of paper. One brilliant set of students thought to slide the paper back and forth through a slit in the box. We called this ‘faxing’ and they loved it!

This year, my co-teacher and I decided to try making this digital since our students have one-to-one Chromebooks. Instead of faxing a piece of paper back and forth, the pairs typed to one another on a shared Google Doc. We also structured the activity as a CER puzzle (Claim, Evidence, Reasoning). The students make observations of the solutions and basically tell each other how their solutions are labeled (the letters and numbers). Then, they collect Evidence by doing mini-experiments on their acetate sheet (for example, “When I mix 4 and 5, the product turns white”). Once they have enough evidence, they can make their Claim, which is something like “10=L, 11=M, 12=K”. In the Reasoning box, they should give explanations for how they used their various pieces of evidence to support their claim. For example: If a numbered solution reacted the same way with two different solutions as a lettered solution, we concluded that the numbered and lettered solution were the same.

## A Great Confidence-Booster and Diagnostic Tool

It was so cool when a lot of my lower students solved the puzzle before the students whom I expected to first! This is because the puzzle requires simple testing of the mystery solutions– for example, when you put a drop of B onto a drop of A, the solutions bubble! Given enough time, almost every pair of 8th graders will either solve the puzzle or have at least cycled through the experimental process to get very close.

During this activity, you will see students’ communication skills at work. Some pairs of students will find a way to communicate what they are doing in ‘their laboratories’ much quicker than other pairs. Some students will figure out way before others that they can/should mix the solutions and make observations of the product. Since it’s hush-silent in the room during this activity, it’s a great time to make your own observations of how your students work independently and together on this task.

You will also be able to assess students’ ability to make observations, record evidence, come to a conclusion, and support their claim with clear reasoning.

## The Prep Work

As Flinn suggests, I like to make this even more interesting by labeling each pair’s set with different letters and numbers (for example, G, H, and I equal 9, 7, and 8, respectively) so that the pairs have to really solve their own puzzle.

You will need:

- white vinegar
- 2% baking soda solution (mix 4 grams of baking soda into 200 mL of water)
- 2% Alum (aluminum potassium sulfate) solution– you can get Alum in the spices aisle of the grocery store or from Amazon (mix 4 grams of Alum into 200 mL of water)
- You will need enough cassette cases so each student has one (I have 24 students in my largest class so I prepped 12 pairs, or 24 total cases)
- thin-stem pipettes (cut off most of the stem)
- a Sharpie marker to label the pipette bulbs and the case pairs
- about 5 acetate sheets (transparency sheets)
- some sort of cardboard dividers to place between students so partners can’t see one another during the activity

I suggest watching Bob Becker’s 10 minute explanatory video to get a better sense of this activity. Also check out Flinn’s directions for prepping the puzzle!

You can grab a **FREE DOWNLOAD** of the MYSTERY SOLUTIONS ACTIVITY PRINTABLE and DIGITAL STUDENT SHEETS plus ACTIVITY OVERVIEW PRESENTATION!

If you try out this activity, let me know how it goes in the comments below! And you may also be interested in checking out my blog post of Engaging Science Activities for the First Days of School!

*This post contains Amazon affiliate links. If you purchase from Amazon after going through these links, I receive a small commission at no extra cost to you.*

## 1 Comment

## Nicole

March 2, 2019 at 10:59 pmThis is amazing! I am planning to use this! Thanks so much for sharing!