This is aligned with the following California State Standards:
Without counting each object, recognize the number of objects in a set (up to four).
Recognize a unit as a group of countable objects. Recognize ten as a group of 10 individual objects or 1 ten. Recognize a group of 10-19 objects as 1 ten and a group of remaining ones and a group of 20 or more objects as multiple sets of 10 and a group of remaining ones. Decompose or represent a given number in terms of tens and ones (e.g., 43 = 4 tens and 3 ones).
Communicate understanding that the digit in the tens place is formed by grouping objects by tens and the digit in the ones place is composed of individual objects. Communicate understanding of how to round numbers to the nearest ten using place-value: the tens place is rounded up if the digit in the ones place equals 5 or more (e.g., 45 is rounded to 50) and is rounded down otherwise (e.g., 32 is rounded down to 30).
Round numbers 0-100 to the nearest ten by using a rounding strategy (e.g., number line, place value).
Round numbers 100 and beyond to the nearest hundred by using a rounding strategy (e.g., number line, place value).