The most important thing in solving problems is the ability to identify the condition (the circumstance of Affairs at the moment) and the question (what happens when the situation changes). The more you need to find, the more manipulations are necessary.
Need to teach the child to identify the main words: given-took, buy-sell, has taken put. To reveal the meaning of the words: if the boy was treated, something gave – he has added, if the girl was taken away, claimed she became paralyzed.
Visibility – compulsory methodically the correct condition of the learning child . Abstract concepts the child is not able to operate, so the first step was to explain on concrete examples. For example, my mom has seven cubes, four she gives to her son and asks to know what she left. Thus, it is important that all manipulations were carried out by the child, be sure to muttering aloud that what he is doing. Thus, use all types of memory: visual, motor, auditory.
When training the tasks you need to tell the kid how to distinguish between part and whole. The meaning of these words can be explained on a concrete example: take an orange and divide it into slices. The fruit itself is the whole and slices – it's part of the whole. A child considers how many parts is orange. Clean half and ask the kid to find out how much is left. He counts, I ask, how else can you find a solution to this task? Correctly, by subtraction. How to know how much would be slices, if to the first part add the second? Right, I need to lay down, get an orange.
The final stage of training the tasks must be the repetition, the analysis of the performed operations. Baby items says, what was the condition, what is the question, what did he do to get the answer. Once the algorithm learned, should be given the same task for independent work.
Start with simple tasks, it is not necessary to require all at once. Child, one way or another, learn to solve problems, most importantly, what attitude will give him such exercises.