Solutions by everydaycalculation.com
This multiplication involving fractions can also be rephrased as "What is 21/40 of 21/90?"
2140 × 2190 is 49400.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40×21/90 21/40×42/90 21/80×21/90 63/40×21/90 21/40×63/90
© everydaycalculation.com