Why does the man call the woman?

W: Hello?
M: Hi, Susie?
W: Oh, hi Tom. What’s up?
M: Sorry to be calling you so late but I’m having trouble with the maths assignment.
W: Don’t worry, it’s not that bad. But I do have to say that I haven’t worked this hard on an assignment all term. I’ve already spent more than two hours on it and I’m still not halfway through it.
M: Well, that’s still farther than I’ve gotten. I have no idea even where to start. I was thinking about calling Professor Johnson.
W: Now? But the assignment’s due tomorrow. He’ll wonder why you waited until now to ask for help.
M: This always happens. I mean, when I first got the assignment, I thought it looked ok and I figured I could do it in two hours. And now, it turns out I can’t even figure out how to get started.
W: Oh...well, do you want to come over? I could show you what I’ve worked out so far, and then we could work on the rest together.
M: Are you sure? I hate to interrupt you. I mean, I don’t want to hold you back.
W: It’s OK. I’m sick of working on it alone. And anyway, if I’m thinking out loud, it’ll probably help clarify the muddy parts for me, too.
M: Thanks a lot. I owe you big on this one. I was afraid I was headed for another bad grade.
W: No problem.
M: See you in a few minutes.
W: Okay. Bye.