x+200=300+400
x+200=700
x=700-200
x=500
k mk nhe
x + 200 = 300 + 400
x + 200 = 700
x = 700 - 200
x = 500
ai k mik mik k lại
x+200=300+400
x+200=700
x=700-200
x=500
x+200=300+400
x+200=100+200+400
suy ra x=100+400=500
x+200=300+400
x+200=700
x=700-200
x=500
k mk nhe
x + 200 = 300 + 400
x + 200 = 700
x = 700 - 200
x = 500
ai k mik mik k lại
x+200=300+400
x+200=700
x=700-200
x=500
x+200=300+400
x+200=100+200+400
suy ra x=100+400=500
500 + x = 100 + 500
300 - x = 300 + 200
400 - x = 200 + 400
b) 200 x 4 = ...... 300 x 2 = ......
200 x 2 = ...... 300 x 3 = ......
400 x 2 = ...... 500 x 1 = ......
100 x 4 = ...... 100 x 3 = ......
100 + 100 + 200 + 200 + 300 + 300 + 400 + 400
x + 400 = 200 + 300
200+x=300+400
100+100+200+200+300+300+400+400+500+500+600+600+700+700+800+800+900+900+?
x + 300 = 400 + 200
x+200=300+400:4
Tính nhẩm:
Cách làm: 200 x 3 = ?
Nhẩm: 2 trăm x 3 = 6 trăm
Vậy: 200 x 3 = 600
200 x 2 = 300 x 2 =
200 x 4 = 400 x 2 =
100 x 5 = 500 x 1 =