How do I do 1.5 divided by -2.5? Round to the nearest tenth

First, you'll need to remember your place values: To round a number to the nearest tenth , look at the next place value to the right (the hundredths). If it's 4 or less, just remove all the digits to the right. If it's 5 or greater, add 1 to the digit in the tenths place, and then remove all the digits to the right.

Idon’t understand this but 90