We look at how addition can be reversed by moving numbers to the other side reversing their signs:
x*3 + 2 = 14 is reversed to x = (14 – 2) / 3.
This enables us to do both forward and backward calculations.
Thus we can consider the classical quantitative literature consisting of word-problems, especially from economy and physics.
Q: How can counting & adding be reversed ?
A: By calculating backward, i.e. by moving a number to the other side of the equation sign and reversing its calculation sign.
Q: Counting ? 3s and adding 2 gave 14.
A. x*3+2=14 is reversed to x = (14-2)/3
Q: Can all calculations be reversed?
x+a = b is reversed to x = b-a
x*a = b is reversed to x = b/a
x^a = b is reversed to x = a√b
a^x = b is reversed to x = loga(b)