My second years have just been revising expanding brackets which they have found a little tricky. To help them to visualise what it means we have been using this little manipulative.
Just drag the two factors onto the edges and then fill in the rectangle to see the result of expanding (multiplying).
eg If you wish to expand 3(x+4), drag three green blocks onto the left and drag one x block and four green blocks onto the bottom. Fill in the resulting rectangle with three x blocks and 12 green blocks and you can see that 3(x+4) = 3x+12
You can click on the picture above to have a go yourself.