Would you be annoyed with this?

[Samiamnot]

I work 0.8 in a lovely school. Agreed to come in on the morning of my day off ti support with Sats as they need more staff for groups. I thought I was agreeing to sitting with a child or a small group and watching them do their tests then going home for the afternoon. I've just found out I'll be teaching my class that day and the person who normally teaches them on my day off will be doing sats. It's SO MUCH MORE WORK than I signed up for AND marking at the end of it so not even like I can just come home. I'm really annoyed about it but don't know how to deal with it. It's such a nice school and I feel really well supported by the head but am annoyed as I didn't agree to this.

Do I just suck it up (and never offer my time on my day off again) or should I speak to the head and rock the boat (tbh I won't do this.

I guess what I really want to know is, can I get away with basic marking in the lessons instead of having to mark afterwards?

put in a timesheet

Agree. Claim the hours

Why don’t you can only do the morning as agreed as you’re not available all day? That’s not rocking the boat if you previously said you were only available in the morning?
Plus claim the overtime.

Speak to the head, not confrontationally though just that there's been a miscommunication and if you're expected to do a full day's teaching rather than half a day of supporting, then you will need paying for that.

If you don't want to suggest extra pay, how about asking for a day in lieu? Have a date in mind and get it in the diary now.

Agree

Ask for some recompense. Maybe say that there must have been a misunderstanding - you were volunteering to support the children sitting their sats not cover lessons. If they want cover they will need to either pay or give time in lieu. I am doing extra during sats to be with my own class. I will be claiming hours or expecting time in lieu. Be polite but assertive.

If you're teaching on your day off you should be paid. No way should you agree to teach for free.

What did they originally ask you to do, how was it worded? Was it in an email/otherwise in writing?

This.
They surely aren't expecting you to work a full day for no pay or no swap ?

I've maybe understood this differently to others but perhaps the OP is getting paid but is annoyed they have to now so a day's teaching rather than support a group. I can understand that - I work part-time for a reason and would give up my day off only in specific circumstances. However it's tricky if she is getting paid as for a full day's teaching she'd be expected to get everything ready and mark (a big job in primary) as opposed to just swanning off after the SAT, even though she'd take home the same pay. I would say something even if it's just so it doesn't happen again. They've taken advantage of your goodwill.

Maybe suck it up on this occasion and be a 'team player' (hate that expression) and never offer your time again having learned a hard lesson in people taking liberties!