The multiplicative identity is a number that when you multiply by it, it does not change what you multiplied.
1 * 78 = 78
1 * 7 = 7
1 * (-9) = -9
Everything you multiply by 1 remains the same.
1 is the multiplicative identity.
Any number you multiply by 0 gives an answer of zero, not the original number, so zero is not the multiplicative identity.
