Hello. On this very website, the home page in fact, there is a calculator with a ± sign in between the 0 and decimal point, and just below the number 2. Click that to make a number negative and click it again to make it positive.
Hello. On this very website, the home page in fact, there is a calculator with a ± sign in between the 0 and decimal point, and just below the number 2. Click that to make a number negative and click it again to make it positive.