These resources have been reviewed and selected by STEM Learning’s team of education specialists for factual accuracy and relevance to teaching STEM subjects in UK schools.

Double sunglasses

Act 1

A video shows two pairs of sunglasses, each with 50% tint. What will be the percent tint for both pairs combined?

Act 3

A video reveals what the combined tint will be.


Using glasses with 5% tint, how many will be needed to achieve a target of 60% tint?

Show health and safety information

Please be aware that resources have been published on the website in the form that they were originally supplied. This means that procedures reflect general practice and standards applicable at the time resources were produced and cannot be assumed to be acceptable today. Website users are fully responsible for ensuring that any activity, including practical work, which they carry out is in accordance with current regulations related to health and safety and that an appropriate risk assessment has been carried out.

Information on the creators and permitted use of this resource is covered by the Category Three Materials - Community Resources section in STEM Learning’s Terms and conditions