Teach Together entry #33: Mathematics – Mathematics – Collecting Data on One Variable Using Any Source with Teacher Ricardo When the data is too large, it's not easy to find the frequencies by mere counting. That's why we use tally marks (|,). Tallies are collected in a set of five. The first four tallies are marked vertically, and the fifth tally is marked diagonally across the already existing four tallies. Today, let's learn how to use tally marks here in Teacher Ricardo's entry for Vibal's #