Thanks Anerteine, i will look at that link!
Portia we have different currency to you guys, no 1s or 2s, without small coins I can't see how money would help. She has no trouble using beads to demonstrate. But she just isn't fast or accurate at all with facts that really are needed for double digit subtraction with regrouping. Subtraction wihin 11-20 is fairly fundamental to subtraction like 73-17, which she understands conceptually but makes computational errors in the small steps (ie 13-7).k
I have to say I don't get your thing about the names making 11-20 harder at all, I'm assuming a personality thing, for me 25-9 is not easier than 15-9, it's dependent on 15-9... But maybe it will make more sense to DD.
I'm thinking of googling for number bond worksheets. Maybe that's what she needs to memorize...
Do you guys still have 5 cent pieces - it is amazing how doing money sums is simplified when you only have 10, 20 and 50 cent pieces. Although I did have to explain rounding to to ds6 the other day and the difference between the rounding most of the shops use and what you would use in maths - so it has added to the complications in that way. And I would really like to be able to use coins for place value explanations.
