Solutions by everydaycalculation.com
This multiplication involving fractions can also be rephrased as "What is 21/40 of 21/42?"
2140 × 2142 is 2180.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40×21/42 21/80×21/42 21/40×21/84 63/40×21/42 21/40×63/42
© everydaycalculation.com