CPD Workshops


by Fellowship Agency January 9, 2019

This activity was created as part of a Gratnells What’s In My Tray CPD workshop for secondary science teachers and technicians to support practical work and delivery of the curriculum. It can be carried out as a stand-alone activity for students or combined with other activities from the session to form a STEM carousel.

You will need (per team of 4):

  • 1 x Deep Gratnells tray with lid
  • 1 x Picture of two woodlice or two live woodlice in a petri dish (handle with care) (A)
  • 1 x Piece of copper pipe in a jar (B)
  • 1 x Strip of litmus paper (C)
  • 1 x Sealed transparent jar with copper sulphate in it (D)
  • 1 x Sealed transparent jar with calcium carbonate in it (E)
  • 1 x Sealed transparent jar with a piece of carbon/graphite in it (F)
  • 1 x Model brain (G)
  • Question cards and labels for all the items
  • Pencil and paper for noting down the answer

This activity also works for individuals or smaller teams, just increase the amount of time allocated to complete it.

This activity can be repeated multiple times, reusing the same equipment for each team.

Tips: Parafilm is great for sealing jars. If you don’t have some of the items on the equipment list, the question cards also show a photograph of the item and can be used alone without a prop, however, some of the questions may be more difficult to answer from just looking at a picture.


  • Follow the instructions on the question cards and labels download.
  • Label all the items with the corresponding question card.
  • Place all the labelled items into the tray and put the lid on.

What to do:

  • Approach the tray and lift the lid.
  • Explore the contents of the tray and answer each of the seven questions (A to G).
  • Substitute each answer into this equation (A + B + C + E + F + G) x D = ?
  • Make a note of the final answer (?) and show your workings.
  • The team closest to the answer gets 5 points, next closest 4 points and so on. Or, or award one point for each correct answer A-G and a bonus point for getting the total correct.
  • Do not open any of the sealed pots or remove any of the question card labels.

Tidy up time:

  • Put all the items back into the tray and replace the lid.


  1. How may legs on two woodlouse = 14 x 2 = 28
  2. What is the atomic number (piece of copper pipe) = 29
  3. Most alkaline number on the pH scale = 14
  4. How many atoms of sulphur in one molecule (Copper Sulphate, CuSO4) = 1
  5. The number of different elements in Calcium Carbonate (CaCO3) = 3,
  6. What is the atomic number (piece of carbon/graphite) = 6.
  7. How many cells? 1 billion, 10 billion or 100 billion (model of a brain) = 100 billion

Total:    (28 + 29 + 14 + 3 + 6 + 100 billion) x 1 =  100 billion and 80 OR 100,000,000,080

Other things to try:

  • Substitute any of the items and questions for ones you have invented yourself. Use this to tailor the activity to the age and ability of your pupils or your current areas of study. Just be sure to adjust the final calculation and answer accordingly. Depending on the age and ability of the pupils, if you make the calculation more difficult, you may need to provide a calculator.
  • Challenge the students to work in pairs or small teams to create their own quiz trays, either open ended or based on a current topic, e.g. the periodic table. Upon completion, the trays can be rotated around the class for everyone to have a go at.

Health & Safety

As with all Gratnells Learning Rooms What’s In My Tray activities, you should carry out your own risk assessment prior to undertaking any of the activities or demonstrations. In particular, see the appropriate CLEAPSS HazCards