Last week, a student I mentor asked what an expression was. Initially, I thought she was referring to the English language, but she was actually asking about algebraic expressions and variables. She was confused by the concept since she understood it in the context of language arts. I was stumped as to how to explain algebraic expressions in simple terms.
Thankfully, there is a ready reference known as the Khan Academy.
Initially set up by Harvard graduate Salman Khan to tutor his relatives by sharing educational videos on YouTube, the website has since expanded to include thousands of presentations.
High-quality videos show experts using tried and tested techniques to explain mathematics and science topics as if you were in the classroom. Other subjects like art and history use images and videos with commentary, so lessons about Donatello's bronze David happen right in the courtyard of the Medici Palace in Florence.
The website is easy to navigate. Users can browse lessons by subject. Topics are carefully curated according to difficulty but it is just as easy to find a single topic with the search box.
After watching the videos, learners can practise the concepts with online exercises that have various levels of scaffolding (Khan Academy calls them 'hints') and immediate feedback. A useful coaching feature allows educators to track how their wards are progressing, with data such as exercises they are struggling with, how much time they spend on the site, and even how engaged and on-task they have been.
Although Khan Academy is mostly aimed at middle-schoolers and up, it has recently added material covering basic addition and subtraction for younger learners.
The website motivates learners by using goals and achievement badges. This is another excellent example of how old school motivational techniques like stars and awards are making a comeback. The badges provide milestones that encourage students to stay engaged and work towards higher levels, since they are also available for their peers to see.
Khan Academy stands out because learners can work on materials at their own pace. They can use it to brush up on classroom topics that they struggle with, or move ahead if they have mastered the skills. They can rewatch videos and pause them at any time.
Verdict: it was great as a quick refresher. Older children will it a useful supplement to classroom material.
Khan Academy is free to register at khanacademy.org