Check the correctness of the equation wavelength = h/mv.
Wavelength = h/mv
λ = һ/mv
h = Planck's constant
m = mass
v = Velocity
λ = wavelength
To check the equation (De Broglie's equation) is dimensionally consistent we use square brackets to mean "the dimensions of" where L, M, T are fundamental quantities of lenght, mass and time respectively.
[wavelength (λ)] = [L]
[h] = [angular momentum] = [L][linear momentum] = [L][M][velocity] =[L][M][L/T]
So we now have
[L] = [L][M][velocity] / ( [M][velocity] )
which simplifies to [L] = [L]
which means the equation is dimensionally correct (consistent).