With addition, start with counting on. That's where you have two piles, six and two. Well, you already know there's six in the one pile, so instead of counting all six of them, you just touch the pile, say "Six...", and then "count on" the other two, touching them and saying "Seven, eight." That's the basic concept. Then, when you've got written problems, start by SAYING the larger number and then "counting on" the smaller one. This works best for ones and twos. Do this a lot, and they'll get the ones and twos quickly. You can even cue them, "That's eight, and two more...." Then work on doubles. They tend to go quickly. Once you got doubles, do "doubles-plus-one"...7+6 is "6+6...and one more". Learn the 10+, which are easy, and then the 9's are "one less". 9+8 is "10+8, and one less". Also, teach "flip-flops" together. 3+8 and 8+3, etc.
This is good info here, we are still working on one of them to memorize the addition facts. Jackie, thanks for the tips. I've got one who still wants to count all instead of counting up. (she's 7) If I try to gently guide her into "you already know this pile is 6..." she shuts down and won't do anything from that point. Do you have any suggestions on how to get past this? She is so stubborn!
Could you "hide" the one pile? Use two hands. "Hide" six in one hand, and show her two more in the other. How many are there in both hands?
We also memorized the multiplication facts in school, but I did not know until I was teaching first ds that all the 9 fact products add up to 9. 9x7=63(6+3=9) I thought that was so cool and it keeps you from thinking, perhaps, that 9x7=65. Did I write that so it could be understood?
You might look at Timez Attack: http://www.bigbrainz.com/ It's a free online game [for the basic game] to teach the times tables. It plays like a video game and so might be a little more engaging than just flash cards. My son and daughter like it. The base game can get a little repetitive, though, so I would recommend doing one level per day rather than trying to run through a bunch all at once.
I love Jumpstart study helpers. http://shop.knowledgeadventure.com/Products/JumpStart-Advanced-Study-Helpers__20211.aspx