Multiplication is a way of adding the same number multiple times. When you multiply 3×3, you're adding the number 3 three times:
3×3=3+3+3=9
So, 3×3=9 means that you're taking three groups of three, which equals 9 in total.
Question: What fundamental theorem of calculus states that if a function f(x) is continuous on [a, b] and F(x) is an antiderivative of f(x), then the definite integral of f(x) from a to b is equal to F(b) - F(a)?