It is common in everyday life to use terms that involve letters, this is a way of abbreviating generalities. and in that idea at school they teach us to use them in different ways.
They letters should be used freely and arbitrarily and the teacher at school should allow students to choose their letters freely when solving problems that merit their use.
In general, the student expects the teacher or the book to indicate which letter to use and this generates certain errors in the use of letters that persist from school to higher levels and hinder the learning of algebra.
For example, to designate the height of a triangle, it is customary to use the letter H, and that is because the initial of the word is used to denote objects; in this case it is said that the letters are used as labels.
Another example is that in which we designate a length by "L" or a circumference by "C", in short, there are countless examples in this regard.
There are other ways to use the letters, this is the case of using them as objects, for example if the letter “a” represents apples, then most people interpret, for example, that 5a means 5 apples when it really means multiplication of "5 for the" a "amount of apples."
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The letters are also used as variables and in most cases the "x" or the "y" tend to be used which are generally used in the context of the equations.
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Letters are also used as constants in certain formulas such as physics, chemistry, among others, where the use of letters as labels is accentuated.
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All these ways of using letters develop cognitive obstacles at the time of the transition from arithmetic to algebra and errors persist to higher educational levels.
