12の性質
かけ算12の段 12×25に注目しよう
- 12 × 1 = 12
- 12 × 2 = 24
- 12 × 3 = 36
- 12 × 4 = 48
- 12 × 5 = 60
- 12 × 6 = 72
- 12 × 7 = 84
- 12 × 8 = 96
- 12 × 9 = 108
- 12 × 10 = 120
- 12 × 11 = 132
- 12 × 12 = 144
- 12 × 13 = 156
- 12 × 14 = 168
- 12 × 15 = 180
- 12 × 16 = 192
- 12 × 17 = 204
- 12 × 18 = 216
- 12 × 19 = 228
- 12 × 20 = 240
- 12 × 21 = 252
- 12 × 22 = 264
- 12 × 23 = 276
- 12 × 24 = 288
- 12 × 25 = 300
- 12 × 26 = 312
- 12 × 27 = 324
- 12 × 28 = 336
- 12 × 29 = 348
- 12 × 30 = 360
- 12 × 31 = 372
- 12 × 32 = 384
- 12 × 33 = 396
- 12 × 34 = 408
- 12 × 35 = 420
- 12 × 36 = 432
- 12 × 37 = 444
- 12 × 38 = 456
- 12 × 39 = 468
- 12 × 40 = 480
- 12 × 41 = 492
- 12 × 42 = 504
- 12 × 43 = 516
- 12 × 44 = 528
- 12 × 45 = 540
- 12 × 46 = 552
- 12 × 47 = 564
- 12 × 48 = 576
- 12 × 49 = 588
- 12 × 50 = 600
- 12 × 51 = 612
- 12 × 52 = 624
- 12 × 53 = 636
- 12 × 54 = 648
- 12 × 55 = 660
- 12 × 56 = 672
- 12 × 57 = 684
- 12 × 58 = 696
- 12 × 59 = 708
- 12 × 60 = 720
- 12 × 61 = 732
- 12 × 62 = 744
- 12 × 63 = 756
- 12 × 64 = 768
- 12 × 65 = 780
- 12 × 66 = 792
- 12 × 67 = 804
- 12 × 68 = 816
- 12 × 69 = 828
- 12 × 70 = 840
- 12 × 71 = 852
- 12 × 72 = 864
- 12 × 73 = 876
- 12 × 74 = 888
- 12 × 75 = 900
- 12 × 76 = 912
- 12 × 77 = 924
- 12 × 78 = 936
- 12 × 79 = 948
- 12 × 80 = 960
- 12 × 81 = 972
- 12 × 82 = 984
- 12 × 83 = 996
- 12 × 84 = 1008
- 12 × 85 = 1020
- 12 × 86 = 1032
- 12 × 87 = 1044
- 12 × 88 = 1056
- 12 × 89 = 1068
- 12 × 90 = 1080
- 12 × 91 = 1092
- 12 × 92 = 1104
- 12 × 93 = 1116
- 12 × 94 = 1128
- 12 × 95 = 1140
- 12 × 96 = 1152
- 12 × 97 = 1164
- 12 × 98 = 1176
- 12 × 99 = 1188
- 12 × 100 = 1200
12 の段は中学受験の算数でかなりよく使います。168 が 12 の倍数だと瞬間的にわかるようになると GOOD!
300 に注目。300 は 12 の倍数であり、25 の倍数。300 は 12 の段の一つの目印になるでしょう。
12 × 25 = 300
という式は
12 × 25
= 3 × 4 × 25
= 3 × 100
= 300
と変形できます。
