Powerpoint problems and models- free downloadable

Frogs

Can these numbers be arranged in the grid so that each row column and diagonal has the same total?

Lightening strikes one of the trees in a square forest.

After one minute, the trees next to it are aflame.

After another minute the trees next to them are aflame… and so on

How long before the whole forest is alight?

Four jugs, each a different size. 900ml of water.

How can you get 3 equal quantities?

JB Mathematics Consultancy

Frogs

Addition and subtraction on a number line- modeling the link between the number line method and the appropriate column method.

Addition and subtraction by partitioning- modeling the link between partitioning methods and the appropriate column methods.