Solutions by everydaycalculation.com
This multiplication involving fractions can also be rephrased as "What is 42/80 of 21/70?"
4280 × 2170 is 63400.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/80×21/70 42/80×42/70 42/80×63/70
© everydaycalculation.com