Bài 1 (trang 69 sgk Toán 2)
Tính nhẩm:
11 – 2 = 12 – 3 = 13 – 4 =
11 – 3 = 12 – 4 = 13 – 5 =
11 – 4 = 12 – 5 = 13 – 6 =
11 – 5 = 12 – 6 = 13 – 7 =
11 – 6 = 12 – 7 = 13 – 8 =
11 – 7 = 12 – 8 = 13 – 9 =
11 – 8 = 12 – 9 =
11 – 9 =
14 – 5 = 15 – 6 = 16 – 7 = 17 – 8 =
14 – 6 = 15 – 7 = 16 – 8 = 17 – 9 =
14 – 7 = 15 – 8 = 16 – 9 =
14 – 8 = 15 – 9 = 18 – 9 =
14 – 9 =
11 – 2 =9
12 – 3 =9
13 – 4 =9
11 – 3 =8
12 – 4 =8
13 – 5 =8
11 – 4 =7
12 – 5 =7
13 – 6 =7
11 – 5 =6
12 – 6 =5
13 – 7 =6
11 – 6 =5
12 – 7 =5
13 – 8 =5
11 – 7 =4
12 – 8 =4
13 – 9 =4
11 – 8 =3
12 – 9 =3
11 – 9 =2
14 – 5 =9
15 – 6 =9
16 – 7 =9
17 – 8 =9
14 – 6 =8
15 – 7 =8
16 – 8 =8
17 – 9 =8
14 – 7 =7
15 – 8 =7
16 – 9 =7
14 – 8 =6
15 – 9 =6
18 – 9 =9
14 – 9 =5
11-2=9 12-3=9 13-4=9 16-7=9
11-3=8 12-4=8 13-5=8 16-8=8
11-4=7 12-5=7 13-6=7 16-9=7
11-5=6 12-6=6 13-7=6 18-9=9
11-6=5 12-7=5 13-8=5 17-8=9
11-7=4 12-8=4 13-9=4 17-9=8
11-8=3 12-9=3 14-5=9 14-8=6
11-9=2 15-6=9 14-6=8 14-9=5
15-7=8 14-7=7
15-8=7
15-9=6