en_tn_condensed/num/03/47.md

five shekels

"about 55 grams of silver". A shekel is a unit of weight equal to about 11 grams.

You must use the shekel of the sanctuary as your standard weight

"You must use the weight of the shekels in the sanctuary as your standard weight". This means that the shekel must weight the same as those in the sanctuary.

twenty gerahs

"20 gerahs." A gerah is a unit of weight equal to about 0.57 kilograms.