Algebra

For a wonderful introduction or review of equations try these excellent Mobile puzzles.

Don Steward has posted this sum and product task (developed in the UK by Barbara Ball and Derek Ball) which would be ideal for a starter. For example find three expressions such that the sum is 5d+5 and the product is 30d².

Picture puzzles – find the value of the objects in the grid.

Try What’s it Worth? from Nrich.
Use the ‘Search by Topic‘ function on Nrich for numerous rich problems.