Download - CALCULO MENTAL 3º
1
2
40 + 30 = 70
4 + 3 = 70
400 + 300 = 700
3
40 - 30 = 10
4 - 3 = 10
400 - 300 = 100
4
46 + 30 = 76
4 + 3 = 76
5
46 - 30 = 16
4 - 3 = 16
6
16 + 11 = 27
16 + (10+1) = 27316 + 11 = 327
7
16 + 9 = 2516 + (+10-1) = 25
316 + 9 = 325
8
16 - 11 = 5
16 – (-10-1)= 5
9
16 - 9 = 716 - (-10+1) = 7
316 - 9 = 305
10
16 + 21 = 27
16 + (20+1) = 27
11
56 - 21 = 35
56 - (20-1) = 35366 - 21 = 345
12
2 x 10 = 204 x 100 = 400
7 x 1000 = 7000
13
2 x 60 = 1204 x 300 = 1200
7 x 6000 = 42000
14
27 x 10 = 27046 x 100 = 4600
79 x 1000 = 79000
15
276 x 10 = 2760
467 x 100 = 46700
793 x 1000 = 793000
16
20 x 50 = 1000
400 x 70 = 28000
17
24 x 2 =48
4 x 2 = 82 x 2 = 4
18
25 x 2 =50
2 x 2 =44 +1 = 5
19
20 / 2 = 10
600 / 2 =300
20
42 / 2 = 21
4/2= 2
2/2= 1
21
642 / 2 = 3216/2= 24/2= 1
2/2= 1
22
156 + 200 = 356
1 + 2 = 356
23
856 - 300 = 556
8 - 3 = 5
24
856 - 101 = 957
856 +100 +1 = 957
25
856 + 201 = 1057
856 +200 +1 = 1057