var1 = "100"
var2 = "-10.5"

# Variable var1 and var2 are strings so the 'plus' operator in this case performs
# the concatentation operation (combines two strings).
print(var1 + var2)

# Converts var1 and var2 to numerical form before the 'plus' operator is applied.
# int (var1): converts the string 'var1' to an integer value.
# float (var2): converts the string 'var2' to a floating point (real number) value.
# Since the inputs to the operator are now numbers rather than strings, the
# mathematical addition operation is performed.
print(int(var1) + float (var2))