In reply to @JanvierUK
@JanvierUK to give an easy way of converting between currencies (for values of 'easy' that apply to mathematicians)
In reply to @christianp
.@JanvierUK for example, the current exchange rate of £1 = €1.20829 is more easily remembered as ζ(1,2)ᵀʰᵘᵉᴹᵒʳˢᵉ/(Lehmerᵀʰᵘᵉᴹᵒʳˢᵉ)