Then, since you know that 15 is equal to 10 plus 5 and that 5 is exactly half of 10, you can quickly calculate the final sale price by addition and subtraction.
Pēc tam, zinot, ka skaitlis 15 ir vienāds ar skaitļu 10 un 5 summu un ka 5 ir puse no 10, mēs varam viegli aprēķināt galējo cenu.