99の性質
かけ算99の段（99の倍数）と計算方法
- 99 × 1 = 99
- 99 × 2 = 198
- 99 × 3 = 297
- 99 × 4 = 396
- 99 × 5 = 495
- 99 × 6 = 594
- 99 × 7 = 693
- 99 × 8 = 792
- 99 × 9 = 891
- 99 × 10 = 990
- 99 × 11 = 1089
- 99 × 12 = 1188
- 99 × 13 = 1287
- 99 × 14 = 1386
- 99 × 15 = 1485
- 99 × 16 = 1584
- 99 × 17 = 1683
- 99 × 18 = 1782
- 99 × 19 = 1881
- 99 × 20 = 1980
- 99 × 21 = 2079
- 99 × 22 = 2178
- 99 × 23 = 2277
- 99 × 24 = 2376
- 99 × 25 = 2475
- 99 × 26 = 2574
- 99 × 27 = 2673
- 99 × 28 = 2772
- 99 × 29 = 2871
- 99 × 30 = 2970
- 99 × 31 = 3069
- 99 × 32 = 3168
- 99 × 33 = 3267
- 99 × 34 = 3366
- 99 × 35 = 3465
- 99 × 36 = 3564
- 99 × 37 = 3663
- 99 × 38 = 3762
- 99 × 39 = 3861
- 99 × 40 = 3960
- 99 × 41 = 4059
- 99 × 42 = 4158
- 99 × 43 = 4257
- 99 × 44 = 4356
- 99 × 45 = 4455
- 99 × 46 = 4554
- 99 × 47 = 4653
- 99 × 48 = 4752
- 99 × 49 = 4851
- 99 × 50 = 4950
- 99 × 51 = 5049
- 99 × 52 = 5148
- 99 × 53 = 5247
- 99 × 54 = 5346
- 99 × 55 = 5445
- 99 × 56 = 5544
- 99 × 57 = 5643
- 99 × 58 = 5742
- 99 × 59 = 5841
- 99 × 60 = 5940
- 99 × 61 = 6039
- 99 × 62 = 6138
- 99 × 63 = 6237
- 99 × 64 = 6336
- 99 × 65 = 6435
- 99 × 66 = 6534
- 99 × 67 = 6633
- 99 × 68 = 6732
- 99 × 69 = 6831
- 99 × 70 = 6930
- 99 × 71 = 7029
- 99 × 72 = 7128
- 99 × 73 = 7227
- 99 × 74 = 7326
- 99 × 75 = 7425
- 99 × 76 = 7524
- 99 × 77 = 7623
- 99 × 78 = 7722
- 99 × 79 = 7821
- 99 × 80 = 7920
- 99 × 81 = 8019
- 99 × 82 = 8118
- 99 × 83 = 8217
- 99 × 84 = 8316
- 99 × 85 = 8415
- 99 × 86 = 8514
- 99 × 87 = 8613
- 99 × 88 = 8712
- 99 × 89 = 8811
- 99 × 90 = 8910
- 99 × 91 = 9009
- 99 × 92 = 9108
- 99 × 93 = 9207
- 99 × 94 = 9306
- 99 × 95 = 9405
- 99 × 96 = 9504
- 99 × 97 = 9603
- 99 × 98 = 9702
- 99 × 99 = 9801
- 99 × 100 = 9900
例えば 99 × 15 は次のように計算します。
99 × 15
= (100 - 1) × 15
= 1500 - 15
= 1485
99 を 100 - 1 として、分配法則から 1500 から 15 を引いています。99 × n は
n00 - n
で求めることができます。
問題
99 × 72
を暗算で求めてみましょう。
解答
7200 - 72 = 7128
