Yes, we're adding one more resource to our math lineup. Catherine is doing well with Singapore Math (and her 'fun' book, 'Key to Fractions') but she sometimes seems a little unsure of the basics behind things like multiplication. My husband and I talked it over and thought we'd order the preceeding Singapore Math texts and workbooks (we had been fairly casual about math up until now remember, no texts). However, that would be almost $100.
I found another solution though.
One of my favourite sites at the moment for homeschooling math resources is Homeschool Math. Maria Miller, the woman behind the site has a whole slew of helpful stuff ranging from a great blog to worksheets to resource listings and even her own line of elementary math ebooks at Math Mammoth. The ebooks are on very specific topics like place value or multiplication and seem like exactly the sort of resource we could use to ensure Catherine has a solid foundation in basic arithmetics. We would still use our Singapore Math texts but pull out Math Mammoth when something, say division, seemed to be giving her trouble. Catherine took a look at some of the sample pages and really liked the simple look and the use of colour. I like that they seems to have a real focus on creating a firm understanding of math skills and concepts, are reprintable and heck, have no shipping costs!
In the interest of disclosure I have to say that Maria's running a contest where, if you mention her books and link to a specific Math Mammoth page, she might just send you a free ebook. I'm not looking for a free ebook however since it's cheaper for me to buy her entire Blue Book series (take a peek here) then win one and buy the rest.