A simple calculation of 3.2 divided by 0.4 minus 1.2 multiplied by 5
There is a simple algorithm for 23.5 times 5.66 minus 23.4 times 5.67
Change 23.5 to 23.4 + 0.1, and then use the law of multiplicative distribution
Or change 5.66 to 5.67 and use the law of multiplicative distribution
How to use the simple operation of 35 times 12 plus 66 times 12 minus 12
35×12+66×12-12
=12×(35+66-1)
=12×100
=1200
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+21+20+19+8+17+16+15...1=()
() is a bracket
On the left are two identical arithmetic sequences minus 22, so the result is: 22 * 23 * 2 / 2-22 = 22 * 22 = 484