This is a workaround to QR-Codes. The basic idea is this: There's a form on a website for users to type short "jump codes". In this example here, it's a guide to bars in Fukuoka; each bar has a 4-digit jump code so that users can find the bar information quickly.

On a student quiz or activity website, each activity has a short jump code. The teacher tells the students what the number is for that night's homework or that class's activity, and the students can find it quickly. (Not as quickly as if it were a QR-Code, but it's pretty fast.)