Riddles and Puzzles

DiScoro writes about inquiry-based learning, digital resources, and ways to encourage higher-order thinking. We focus on STEM education and the use of technology.

Puzzles and riddles that are fun. They require language skills, understanding, logical thinking and can be solved individually or in groups. The Brainzilla website offers a number of ‘Zebra’ puzzles and riddles. An easy one to start with is Movies Night and a pretty difficult one to solve is Einstein’s Riddle. Brainzilla puzzles and riddles are suitable for K4-10.

It is advisable to print out the riddles and puzzles, as the solutions can easily be found online. You can help the pupils to organise their thinking by providing a card for every clue and a stack of cards for the values given. Allow pupils to work together, because not all will enjoy the puzzles if they get stuck.

More similar puzzles can be found on Math is Fun under the so called ‘Einstein Puzzles’. The vocabulary used in the clues here is more suitable for K8-12.

Visualisation of so called ‘Einstein’s Riddle’ which can be found on many websites.



Chemistry: pH scales and acidity

DiScoro writes about inquiry-based learning, digital resources, and ways to encourage higher-order thinking. We focus on STEM education and the use of technology.

The PHET simulation pH Scales enables students to experiment with acidic and basic fluids.

Note that pH scale and acidity are complex concepts for students especially for primary school pupils. A lower pH value means more ‘acidic’ and a higher value means less acidic, or more ‘basic’.  Neutral is indicated by the pH value 7.0.

However, the simulation can help the students to familiarize themselves with the concept(s). The simulation can be used in grade 6 or 7. Depending on how much time you wish to spend and how much structure you wish to give, in addition to the simulation, you could encourage the students to experiment and discover the basics about pH values in fluids and its application in every day life.

Suggestions for tasks and experiments:

  1. Check out the different fluids available.
    Rank the fluids from most basic to most acidic before you start measuring. Write down your estimation.
  2. Measure the pH values for the fluids given and write the results in a table.
    Which fluids are closest to pH 7.0?
    What does it mean if  the pH value of a fluid is close to 7.0?
  3. Use water to dillute the fluids and try to make a fluid that is closest to 7.0.
    Write down what you have done to reach your result.
    Make a screencast of your closest result(s) and print it out.
  4. Can you dillute a basic fluid with water to a pH value below 7.0?
    Can you dillute an acid fluid with water to a pH value above 7.0?
    Try to explain the result?

Think beyond the simulation.

  1. How could you make an acidic fluid basic? In other words, how could you for example change the pH value of an acidic fluid from 5.0 to 7.5?
  2. a. Your body functions best if the pH value is neutral. How does your body manage this?
    b. With the knowledge about the pH value of your body, how can you support your body to remain healthy?

pH value paper strips

In addition to the simulation students could use pH paper strips to measure the acidity of fluids. It becomes particularly interesting if the fluids you use can be tasted. Students can describe the taste they experience. Use for example coca cola or other fizzy drinks, fruit juice, tea, milk, coffee, water. This real life experiment makes it possible to neutralise an acid/basic fluid using other chemicals, for example by adding bicarbonate (baking soda) to an acidic fluid.

battery hydrometer

Another interesting tool is a battery gravity hydrometer, which actually measures the acidity (pH value) of the battery acid. You could also say that it measures the gravity of the battery fluid. Together with a Volt meter it is used to check if the battery is charged and in good condition If your battery is fully charged the pH value should be near 1.28. If the battery is discharged, the pH value will be near 1.14. The battery hydrometer only measures accurate with pH values around 1.2. So is useless to measure pH values over 2.

More PHET simulations. See also Balancing Act, The moving man, Energy skate park, and Density and Buoyancy.

 Purchase  Free
 Hardware  PC, iPad
 Requirements  browser


Video Science

DiScoro writes about inquiry-based learning, digital resources, and ways to encourage higher-order thinking. We focus on STEM education and the use of technology.

Video Science produced by by Science House offers a large number of short videos on experiments. The videos focus mainly on chemistry, but some videos are about phenomena from physics or other science areas.
Students can watch the video’s or carry out the experiments themselves., although some experiments require substances or equipment that will not be readily available. For you as a teacher the videos may inspire you to let show students the experiments. Of course it is even more more interesting and instructive if the students carry out experiments themselves in class.

The future for industry and society lies in recycling, and even a step further ahead in cyclic production, and cradle-to-cradle production. Particularly interesting are therefore experiments such as “Green plastic” and “Recycling paper”.

The latest App (version 4.0) is designed for iOS 6. Unfortunately the App does not work on iOS 11. Hopefully this will be resolved soon.

 Purchase  Free
 Hardware  iPhone, iPad
 Requirements  iOS 6  (not working on iOS11 !)

Train your Phrases Verbs

DiScoro writes about inquiry-based learning, digital resources, and ways to encourage higher-order thinking. We focus on STEM education and the use of technology.

This time we write about an App that may be useful for learners of English as a second language. The App The Phrasal Verbs Machine (Cambridge University Press) enables non-native speakers to learn and train the use of Phrasal verbs. Phrasal verbs are two part verbs. They consist of a verb + an article and or preposition. The article/preposition often changes the meaning of the verb. Read more on the Brititsh Council website and on wikipedia.
The latest version supports 17 different languages, which means that the phrase is translated and the explanation is given in that particular language. The App has a strong visual component with a short animation showing the meaning of the phrasal verb. A disadvantage is that more advanced students of the English language will quickly master all the 100 phrasal verbs.


  • run into
  • look after
  • dress down
  • hand in
  • look forward to

Screendump of the viewing part
 Purchase  Free
 Hardware  iPhone, iPad, Android tablet and smartphone
 Requirements  iOS 6 or higher version,  Android 2.2 or higher

FlaskFiller simulation

glazenFlaskFiller, or rather GlassFiller, is a simulation which enables teachers and students to experiment with and reason about the relationship between the shape of a glass, and the change in speed while filling it up (time vs height of the liquid in the glass).


The simulation program enables the user to

  • Select the horizontal axis’ quantity, which is one of height, time, volume, or rising speed.
  • Select the vertical axis’ quantity, which is one of height, time, volume, or rising speed.

Note that you can select the same quantity for both axes, which can make for an interesting topic of discussion. See some screenshots below.

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Read the information about the simulation and how to use it on FaskFiller Education.
Read the Research done on FlaskFiller software used with grade 5 pupils.

The simulation has been used with grade 5 pupils in a one-to-one setting. When using this simulation in class you might want to use a hands-on experiment first, whereby you use a measuring cup to fill up glasses with different shapes. Let the pupils measure, observe and reason about what is happening with the different glasses.

Afterwards let the pupils experiment with the simulation based on clear questions/tasks. Students should be encouraged to record their findings and discoveries on a worksheet.
Most grade 5 pupils understand the principle of instantaneous speed, but lack the vocabulary. After experimenting in small groups, you could start the simulation on your SmartBoard and discuss the findings. Here the pupils will learn to extend their vocabulary and express what they see and think. Vocabulary: (rising)speed, volume, height, shape, cola-flesjetime, timelap, decrease/increase in speed of height of liquid visible in the graph.
After experimenting and discussion, pupils should for example be able to match a glass (or bottle) with a graph and vice versa.

The simulation can be used from grade 5 up to grade 10 depending on the tasks given.

The simulation program is available online as an HTML file, but can also be downloaded for off-line use.

 Purchase  Free
 Hardware  PC
 Requirements  browser

Simulation game: Fishbanks

overfishing_500Fishbanks – a Renewable Resource Management Game is a simulation program and management game from MIT. The game targets the dilemmas surrounding the exploitation of natural resources, such as fish, clean water, fresh air. These resources are not owned by anybody, yet can easily be depleted by some big industries. This is also know as The Tragedy of the Commons.

The game is about subject areas such as: economy, management, resource management, and environmental studies.

You can try out and viw part of the Fishbanks simulation program without registration. Educational institutes can use the simulation for free after registration (administrator).

Below a introductory video of the previous version of the game on The Tradegy of the Commons.

The game is suitable for higher education classes and possibly in grade 11 and 12.

 Purchase  Free for educational institutes
 Hardware  PC
 Requirements  browser

Pattern problems

Pattern problems are a relatively new phenomenon in mathematics education. They can be used both for early algebra in primary school as well as in secondary school. At primary level students reason and come up with a description of how the figure or pattern grows using word formulas. At secondary school level, students can be encouraged to describe the formula for the nth pattern using symbols for the variables.

figure numbers

Two applets from the Freudenthal Institute make it easy to experiment with pattern problems:
Spotting number problems, if you wish to work with given patters
Spotting numbers, if you wish the students to design their own patterns

Introduce a pattern to the class and ask them to look at it first. Then ask them: How do you see the pattern grow?

For the example below we have used the applet Spotting Numbers and coloured in blue the different views students could have on how the pattern grows.

Thereafter students can explore:

  • With how many dots does the figure grow?
  • What about the 20th or 50th figure?
  • How many dots are required?
  • How many dots are on the base?
  • Can you describe a ‘rule’ for the growth?
  • Can you describe a formula for finding the nth figure?

Information on the applets: Spotting numbers and Spotting number problems.

 Purchase  Free
 Hardware  PC
 Requirements  browser, JAVA