1.NBT.A.2 Grade 1 · Number and Operations in Base TenUnderstand that the two digits of a two-digit number represent amounts of tens and ones.Common Core State Standards for Mathematics, as adopted in the Massachusetts Curriculum Framework for Mathematics (2017), Grade 1.
Play the game: Count On, Count BackSteps 16, 17 of the ColorMyMath curriculum · free, 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.
Step 16Adding 1: counting to 25Step 17Subtracting 1: counting back from 25Step 21Adding 1: counting to 301.NBT.A.1Count to 120 starting from any number; read and write those numbers1.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 head1.NBT.C.6Subtract multiples of 10 from multiples of 10ColorMyMath · 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.