Class teacher · Head teacher / Administrator
Taking the register, reading the summary, and texting parents the same day.
Academics → Attendance register. A class teacher marks their own stream. Pick the date, mark who is absent, save. Everyone not marked absent is present.
Academics → Attendance summary. Worst attendance first, because that is the list you are actually looking for. It shows days present, days registered, and a percentage of the days that were taken.
Two of the SMS alerts come from here: same-day absence, which is the one parents value most, and a weekly or monthly summary. Both are sent by you from the SMS screen — nothing sends on its own, because a message that spends money unattended is its own risk.
See Texting parents.
Off by default. Turn it on under Settings → Attendance and the parent portal gains an attendance section for each child.