A simple calculation of 378 / 265 × 194 / 378 × 265 / 194
Using the law of commutation of multiplication
So the original formula is simplified
378÷378×(265÷265)×(194÷194)
=1x1x1
=1
Simple calculation of 12 * 21
zx
12×(20+1)
=12×20+12×1
=240+12
=252