There are many ways in which you can use either specific software or a general spreadsheet program such as Excel to remedy this situation. For example, Maths Frames, from Semerc, is an excellent resource which can be used, even by inexperienced teachers, to help children explore areas of numeracy.
The program provides scenarios in which children can experiment. In the garden centre, for example, children could be asked to find out how much it would cost to germinate seeds or to investigate how a fixed budget could be spent to improve a garden (Ground Force beware!). The scenarios can be adapted to incorporate local data.
The many programs available from SMILE are also a rich source of ideas for investigating. The latest pack (Number 8) of MicroSmile for Windows, contains nine programs on numeracy. Programs, such as Number Lines and Ten Sprint will help children to develop strategies for applying their knowledge of numbers as well as practising number bonds.
Smile Pack 4 also contains programs not only to complement work on numbers, but also to develop pupils' ability to make predictions and explore relationships. Predict is, unsurprisingly, one such program, where children enter numbers and have to guess the rules that are being used by the program to produce the output. Define and Identify deal with the properties of numbers (odd, even, square and so on).
Although many of the programs in Maths Puzzles are familiar (Frogs, Tower of Hanoi and so on), they are a rich source of investigative work and lead to either an algorithm or a general rule.
Finally, you may well be competent enough to set up a spreadsheet, in Excel or similar programs. If not, it is fairly easy to learn how to do so, and there are several books which give examples of how to use spreadsheets in maths (for example, Mathematics Through Spreadsheets from the Mathematical Association).
A program like Predict is straightforward to produce. Set up a cell for the input number, enter a formula in the cell labelled for the output and then hide the formula. Or why not develop the skills of making and testing hypotheses by using a sheet in which a starting number and finishing number are given.
Pupils have to explore how to jump from the start to the end in a sequence and to find how many such sequences there are. This can, of course, be extended by using a different starting point.
Older or more able pupils can set up their own spreadsheets to explore situations like being asked to run a drinks stall at the summer fair. They will need to enter formulae to calculate costs and income, and can use the program to draw a graph showing the break-even point and profit made. Generating patterns such as Pascal's Triangle, the Fibonacci sequence or triangle numbers can be performed on a spreadsheet and children will benefit from learning how to do this themselves, because they will be forced to focus on the relationships between the numbers.