Answer all the questions below and press submit to see how many you got right.
Addition : Addition is the mathematical operation that describes increasing a number by an amount equal to a second number. The mathematical symbol for addition is the plus sign $+.$ The term addition is also used for a generalization of this basic operation on numbers to functions, vectors and matrices.
Negative : A number is negative if it is $\lt 0.$
Number : A number $x$ is a mathematical symbol representing a quantity.
Zero : The number 0.
$8+?=0$
Subtraction : Subtraction is the mathematical operation that describes decreasing a number by an amount equal to a second number. The mathematical symbol for subtraction is the minus sign $-.$ The term subtraction is also used for a generalization of this basic operation on numbers to functions, vectors and matrices.
$61-61-61=?$
Plus : Plus is either a symbol or another word for addition.
$-89+89=?$