I believe that Geogebra and Desmos are staple tools for teaching maths. All trainees should complete their ITT year with a high degree of confidence in using these in my opinion. I have written a few posts about using Geogebra.
But there are other very useful tools available which are great for specific topics. Using these can be quicker than starting from scratch in Geogebra. All these sites are free, don’t require log-ins and don’t use Java so should work OK straight from the browser.
Mathsbot
There is an impressive and growing collection under both the “Manipulatives” and “Tools” section on Jonathan’s site.
The ones I use most:
Geoboard – great to have on the screen when pupils are using actual Geoboards
Cuisenaire Rods – for all sorts of things, here for equivalent fractions
Number line with fractions
Zoomable number line
Fantastic for decimal place value and questions like “Give me a number between 3 and 4, give me a number between 3.5 and 3.6” for example.
Number line with bridging.
This is a new find which I think could be really useful for teaching negative numbers
Polygon explorer
You can achieve the same thing on Geogebra but this site has it already all set up for you.
Percentage-Fractions-Decimals Grid
This grid is highly flexible and can be used for a range of topics including equivalent fractions as well as decimals and percentages.
NRICH
A variety of interactive tools specific to NRICH tasks.
I particularly like Shifting Times Tables which I use to teach sequences:
There are lots of other sites with more of these including Visnos, PhET, The Math Learning Center.