#### Answer

12,523

#### Work Step by Step

To add numbers on a calculator, first locate the buttons marked +, and = or ENTER. To add two numbers, input the first number you wish to add, then press the + button. Then input the second number you wish to add, then press the = or ENTER button. To add 465+9888+620+1550, press the following buttons in the following order:
4, 6, 5, +, 9, 8, 8, 8, +, 6, 2, 0, +, 1, 5, 5, 0, =