Similar to 超数学
 - 1−2+4−8+…1 − 2 + 4 − 8 + ⋯
 - 2次過程
 - 2次元Two-dimensional space
 - 2の平方根Square root of 2
 - 2の冪Power of two
- 2の補数Two's complement
- 2部グラフBipartite graph
 - 3次元Three-dimensional space
 - 3値論理Three-valued logic
 - 3人旅人算
 - 4つの4Four fours
 - 5項補題Five lemma
 - 6の平方根Square root of 6
 - 7の平方根Square root of 7
 - 8の字結び目Figure-eight knot (mathematics)
 - 9項補題Nine lemma
 - 1/6公式
 - 10の平方根
 - 15・290定理15 and 290 theorems
 - 1-形式One-form (differential geometry)
 - 1の分割Partition of unity
 - 2-形式Two-form
 - 2の12乗根Twelfth root of two
 - 2の自然対数Natural logarithm of 2
 - 2の立方根
- 3人の子供の年齢のパズルAges of Three Children puzzle
 - 4次元多様体4-manifold
 - 68–95–99.7則68–95–99.7 rule