The type of mathematics taught in schools is often criticised for being irrelevant to students' lives and not based in "real life". This article is Part 1 of a three part report that documents the findings of a research project that investigated the mathematical calculations completed by adults in their everyday, non-occupational lives in an Australian context. Outlined here are the findings that emerged from analysing data gathered from 160 participants who were asked to describe three of their most typical types of mathematics calculations. Next, they completed a daily log of their everyday mathematics calculations. In all, details of over 1200 calculations were collected during the first stage of the study and these calculations are the focus of this article.