subtract the black knight' -coordinate and white knight' -coordinate the black knight has to move along the -axis by four spaces subtract the black knight' -coordinate and white knight' -coordinate the black knight has to move along the -axis by two spaces by doing some math with the coordinate numbersyou can figure out the distances between two coordinates negative numbers cartesian coordinates use negative numbers negative numbers are numbers that are smaller than zero minus sign in front of number shows it is negative - is smaller than and - is smaller than - if you think of regular numbers (called positive numbersas starting from and increasingyou can think of negative numbers as starting from - and decreasing itself isn' positive or negative in figure - you can see the positive numbers increasing to the right and the negative numbers decreasing to the left on number line figure - number line the number line is useful to see subtraction and addition done with negative numbers the expression can be thought of as the white knight starting at position and moving spaces over to the right (addition means increasingwhich is in the right directionfigure - moving the white knight to the right adds to the coordinate as you can see in figure - the white knight ends up at position this makes sensebecause is subtraction is done by moving the white knight to the left subtraction means decreasingwhich is in the left direction would be the white knight starting at position and moving spaces to the leftlike in figure -