Working systematically

There are three tables in a room with blocks of chocolate on each. Where would be the best place for each child in the class to sit if they came in one at a time?

Can you arrange the digits 1, 1, 2, 2, 3 and 3 to make a Number Sandwich?

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

Ten cards are put into five envelopes so that there are two cards in each envelope. The sum of the numbers inside it is written on each envelope. What numbers could be inside the envelopes?

On the graph there are 28 marked points. These points all mark the vertices (corners) of eight hidden squares. Can you find the eight hidden squares?

Can you make doughnuts by matching these fractions, decimals and percentages?

Place the 16 different combinations of cup/saucer in this 4 by 4 arrangement so that no row or column contains more than one cup or saucer of the same colour.

These points all mark the vertices (corners) of ten hidden squares. Can you find the 10 hidden squares?