Numbers to 20
Lessons in this chapter
About Numbers to 20
Joy of Numbers reopens the numbers to 20 that kindergarten introduced, but asks for something harder: not just saying them in order, but representing, comparing and positioning them.
Represent Numbers up to 19 is about showing the same number in more than one way, as objects, as a written digit and as tens and ones. A first grader who can show 17 three different ways understands it as a quantity rather than a word in a sequence.
Identify Before, After and Between within 19 and Compare Numbers to 19 then put those numbers in order and ask which is larger. By 1st grade this should not involve counting from one each time, which is the shift this chapter is driving.
Find Ordinal Numbers to 20 adds something genuinely new: first, second, third and so on, which describe position rather than quantity. Kids often get the two confused, because “third” and “three” sound related but answer different questions, and keeping them apart is most of what this lesson is for.
Each of the four lessons opens as a worksheet in the page. Represent Numbers up to 19, Compare Numbers to 19 and Find Ordinal Numbers to 20 give 1st graders math problems that ask for the same numbers in several different ways, which is what separates this chapter from the kindergarten one. All four are free and scored as you go.
Frequently asked questions
Four lessons. Represent Numbers up to 19 asks for a number shown in more than one way, Identify Before, After and Between within 19 places it in order, Compare Numbers to 19 asks which is bigger, and Find Ordinal Numbers to 20 introduces first, second and third, which describe position rather than quantity. The counting and comparing sit in Number and Operations in Base Ten (1.NBT); ordinal numbers are not something the Common Core asks for in first grade.
How to represent them in more than one way, put them in order, say what comes before, after or between, compare two of them, and use ordinal numbers like first and fifth.
A cardinal number answers how many, so three apples. An ordinal number answers which position, so the third apple. Find Ordinal Numbers to 20 is the lesson that separates them.
Very. The ordinal forms are a separate set of words and several of them are irregular, first, second and third especially. Using them out loud in daily routines is what fixes it.
Kindergarten built the counting sequence. This chapter asks kids to use it: represent a number in several forms, compare two numbers without recounting, and add ordinal position on top.
Because 1 to 19 is the range where tens and ones first matter, and twenty starts the next pattern. Ordinal numbers go to 20, and Numbers to 120 extends the counting range later in the year.