(15 *( 178 + 5) +90) * 7 =19845
1. (178+5) = 183
2. 15*183= 2745
3. 2745+90= 2835
4. 2835*7=19845
486 : 9 * (46 + 54) : 10 =540
1.46 + 54 = 100
2. 486:9=54
3.100:10=10
4. 54*10=540
624268 - 13965 + 190008=800311
1. 624268 - 13965 = 610303
2. 610303 + 190008 = 800311