Without the use of algorithms, this 4 week unit systematically introduces two-digit addition with regrouping (week 1), and two-digit subtraction with regrouping to (weeks 2 and 3). Week 4 has five two-page reviews of the previous 3 weeks. Each two-page lesson is organized to include multiple methods: number lines, strip diagrams, drawings of ones and tens, and expanded form. An addition test and a subtraction test is included for your convenience. This unit uses Texas process TEKS 2.1B,C,D,E,F and Texas TEKS 2.4D Generate and solve problem situations for a given mathematical number sentence involving addition and subtraction of whole numbers within 1,000.