Texas TEKS Standards
TX.111.13. Mathematics, Grade 1.
(1.3) Number, operation, and quantitative reasoning. The student recognizes and solves problems in addition and subtraction situations. The student is expected to:
1.3 (B) Use concrete and pictorial models to apply basic addition and subtraction facts (up to 9 + 9 = 18 and 18 - 9 = 9).
(1.5) Patterns, relationships, and algebraic thinking. The student recognizes patterns in numbers and operations. The student is expected to:
1.5 (D) Use patterns to develop strategies to solve basic addition and basic subtraction problems.