You earn 1% on purchases. They credit you 10 points for every dollar and then redeem them at 1000 per dollar. So you always round off during earning (losing the last digit since you only get credit for the dollars and tens column after the decimal) and redemption (never being able to use the value of the last digit since int would be a tenth of a cent).
But, the 1% credit you get back is 5% on Mondays & Tuesdays (with the current In Store promotion) - so you would get 50 points for every dollar you spend in that case.
VIP status apparently can get that to 15% on occasion during "events" - but I am not there yet.
And back to the original question which can be interpreted two ways - points per dollar earned AND points per dollar used.
When USING points they are 1,000 points for every dollar you redeem.
But be aware that every dollar you redeem does not count towards coupons that have a minimum purchase. Stacking coupons is not always the issue when a deal is not kicking in at the register; not spending the minimum $10 or $30 for certain offers will prevent them from kicking in. (i.e. you have $50 in points; you are buying a $47 item; you can only use $17 (17k) in points so that you SPEND $30 to use a coupon with a $30 spend minimum OR use only $37 (37k) points so you SPEND the $10 minimum for that coupon.)
Some expire before others.
You may want to use the big one first and save the smaller one if you know you will be back soon.