Oblicz sprytnie 43×5= 8×41= 45×6 50×123 1200:25 952:4 6400:50 840:5

43*5=215 8*41=328 45*6=270 50*123=6150 1200:25=48 952:4=238 6400:50=128 840:5=168

43*5 = (40+3)*5 = 200+15 = 215 8*41 = 8*(40+1) = 8*40 +8*1 = 320+8 = 328 45*6 = (40+5)*6 = 40*6 + 5*6 = 240 +30 = 270 50*123 = 50*(100+20+3) = 50*100+50*20+50*3 = 5000+1000+150 = 6150 1200:25 = (1000+200):25 = 1000:25 +200:25 = 40 +8 = 48 952:4 = (800+152):4 = (800+160-8):4 = 200 +40-2 = 238 6400:50 = 640:5 = (500 +100 + 40) :5 = 100+20+8 = 128 840:5 = (500+300+40):5 = 100+60+8=168