Mental Math: 10 More and 10 Less to 120

111.3(b)(5)(C)Texas Essential Knowledge and Skills (TEKS) · Math · 1st Grade

use relationships to determine the number that is 10 more and 10 less than a given number up to 120;

111.3(b)(1)(C)Texas Essential Knowledge and Skills (TEKS) · Math · 1st Grade

select tools, including real objects, manipulatives, paper and pencil, and technology as appropriate, and techniques, including mental math, estimation, and number sense as appropriate, to solve problems;