In this lesson, students learn that 10 is the first two-digit number made of 1 ten and 0 ones. They compare and order numbers from 0 to 10, understand place value, and decompose numbers up to 99. The lesson explains the difference between one-digit and two-digit numbers, introduces counting in tens up to 100, and teaches comparison using the terms more than, less than, and equal to. Students also practice ordinal numbers, counting objects, matching one-to-one, and comparing groups.