Why $k$ is chosen to be unitless?
1394
How do we know that $F = ma$, not $F = k \cdot ma$
104753
$\sum_{k=1}^nH_k = (n+1)H_n-n$. Why?
112658
Difference between $\sum_{i=1}^{k}{\frac{s_i}{kn_i}}$ and $\frac{\sum_{i=1}^{k}{s_i}}{\sum_{i=1}^{k}{n_i}}$
116913
Whats the difference between the following? $n+k-1 \choose k$ ${{n+k-1}\choose{k-1}}$ ${{n+k-1}\choose{n}}$
24072
Intuitive explanation of why $\dim\operatorname{Im} T + \dim\operatorname{Ker} T = \dim V$
140437
If $a_0\in R$ is a unit, then  $\sum_{k=0}^{\infty}a_k x^k$ is a unit in $R[[x]]$
46211
$(K[x,y,z]/(x^2+y^3+z^7))_{(x,y,z)}$ is a UFD.
109117
what value of K does the system have a unique solution
34712
Decomposable elements of $\Lambda^k(V)$
50656
Intuition behind $k$-algebra, $k$-algebra morphisms?
156679
$K[X,Y]/(XY-1)$ not isomorphic to $K[T]$
15137
Does $IJ=IK\implies J=K$ always hold for integral domain and finitely generated nonzero ideal $I$?
24615
Why should transcendental functions and their arguments be dimensionless?
115585
Do Boolean rings always have a unit element?
81238
Is $O(2)$ really not isomorphic to $SO(2)\times \{-1,1\}$?
80202
Why is $[0, 1] \cap \mathbb{Q}$ not compact in $\mathbb{Q}$?
18484
Show that $k[x,y,z]/(xz-y^2)$ is not a UFD.