{And when they were filled} (h(9373) de enepl(8873)th(8873)an). First
aorist (effective) passive indicative of empimpl(886d)i, old verb
to fill in, to fill up, to fill completely. They were all
satisfied. The Synoptics have echortasth(8873)an like  Joh 6:26 
(echortasth(8874)e). {Gather up} (sunagagete). Second aorist
active imperative of sunag(935c), to gather together. {Broken
pieces} (klasmata). From kla(935c), to break. Not crumbs or scraps
on the ground, but pieces broken by Jesus ( Mr 6:41 ) and not
consumed. {Be lost} (apol(8874)ai). Second aorist middle
subjunctive of apollumi with hina in purpose clause. Only in
John. There was to be no wastefulness in Christ's munificence.
The Jews had a custom of leaving something for those that served.