Hi Meera!

The layout for some of the courses has changed a little.  We still have everything like Preschool, Kindergarten, and 1st Grade, they're just a little hidden.  If you click on the Courses drop-down menu, then click "Math: Pre-K - 8th Grade" directly below "Courses", it'll take you to all of the early development math courses, including 1st Grade, which goes over things like place value, addition and subtraction, and data and measurement.

Hope this helps!  Let me know if you have any other questions.

Elijah