TEACHING AID (16K ZX80)
by J J Bartolo
from Your Computer (August/September 1981), pages 63-65

I compiled this program to be used in conjunction with a ZX-80 with
expanded memory as a teaching aid for children who are taking their first
steps in arithmetic. Although it has been presented to deal with simple
addition, it can be altered easily for simple subtraction, division and
multiplication.

The statements entered throughout the program, such as in line 1040, "that
was not too good", are only guides and any relevant comment can be entered
provided there is sufficient memory space available.

When the program is run, the computer asks you to enter two numbers. It
will then pick two random numbers within the ranges one to the numbers
entered. Then it adds these numbers together and displays the correct
answer with three random alternatives and randomly labels them A, B, C and
D in typical multi-choice format.

The child now takes over and is asked to choose the correct answer. If he
or she chooses correctly, the score is incremented and a new sum generated
and displayed. Of course, if the child should choose an incorrect answer,
the wrong score is incremented, displayed and the child invited to try
again. The sum will remain unaltered until a correct answer is found.

A total score with 10 correct answers more than incorrect ones is rewarded
by the remark, "These seem to be easy for you". The computer is then
instructed to multiply the numbers initially entered by two, thus making
the sums slightly more difficult. After another successful batch of 10
answers correct more than wrong ones, the numbers are again multiplied by
two. This sequence continues until 50 correct answers more than wrong ones
are attained.

The program is then stopped and a message given. If desired, new starting
values can be entered so that the child can continue. If the child has
difficulty in choosing the correct answer as a result of being uncertain of
the sums and has a score of 10 incorrect answers more than correct ones,
the numbers entered initially are divided by two making the sums simpler.

If the child is still unsuccessful, the program is stopped and a message
given. When the program is stopped by pressing the "S" key, the computer
sums up the child's progress and stops the program.
