Basic Definitions: Finding the opposite number

What is the opposite number of $5$

$-5$

What is the opposite number of $87$

$-87$

What is the opposite number of $0.7$

$-0.7$

What is the opposite number of $-7$

$7$

What is the opposite number of $-0.25$

$0.25$

What is the opposite number of $-\frac{8}{7}$

$\frac{8}{7}$