I've ever seen - it is the most practical, common-sense approach!
I esp. love the way it begins with learning about "decimal street" & who lives there - the "ones" in the green house, the "tens" in the blue house, and big red house is where the "hundreds" live! Only 9 can live in the house - 9 chairs, 9 beds, 9 etc. They begin by learning that the number on the page represents "something" & they place a unit (one) block on the page under the number to reinforce the concept. "Place" and "value" are taught from the beginning also, and from there - he builds and builds so that your child always know "why" this is that is done a certain way.
Oh! If only I had been taught this way! I don't recall ever using manipulatives in school - just do it like this to get this answer - and so I did, never completely knowing "why" so when I got stuck or confused, I rarely figured my way out, esp. word problems.
Also, as your child learns new skills, they are always practiced so that you don't have to review or relearn - it stays fresh.
We have used MUS from the beginning and we will not change! It is wonderful!:D
I would love to tell you more of why I love this curriculum - anyone email if you're really interested - (no, I do not sell MUS)