1.NBT.C.6 Grade 1 · Number and Operations in Base TenSubtract multiples of 10 in the range 10–90 from multiples of 10 in the range 10–90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship…Common Core State Standards for Mathematics, as adopted in the Massachusetts Curriculum Framework for Mathematics (2017), Grade 1.
Play the game: Tens Up and Downfree, no sign-up →Past nine, color tells you which place a digit lives in. A ten is a triangle of ten dots; the number of triangles is the tens digit, so 34 is three triangles and four loose green dots.
Every page is free and open — nothing to install, no account, and it works on a phone or a classroom board. Every number has its own color: 1 red, 2 orange, 3 yellow, 4 green, 5 blue, 6 purple, 7 brown, 8 pink, 9 cyan, and a number is that many colored dots.
1.NBT.A.1Count to 120 starting from any number; read and write those numbers1.NBT.A.2The two digits of a two-digit number are tens and ones1.NBT.A.3Compare two-digit numbers with >, = and <1.NBT.C.4Add within 100 using place value; sometimes a ten is made1.NBT.C.5Find 10 more and 10 less than a two-digit number in your headColorMyMath · getridoftheteacher.com · every number has its own color, and a number is that many colored dots. Matching a game to a standard is a judgement call; the official text is at doe.mass.edu.