Solutions by everydaycalculation.com
690 - 2190 is -16.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 12/90-21/90 6/90-42/90 18/90-21/90 6/90-63/90 30/90-21/90 42/90-21/90
© everydaycalculation.com