Teaching first grade place value with tens and ones

A first grader looks at 34 on a worksheet and reads it correctly. Thirty-four, no hesitation. Then you hand her a tub of linking cubes and ask her to build it, and she counts out seven cubes: three, then four more. She can say the number. She does not yet know what the digits are worth. That gap is the reason place value gets its own week in first grade math, and it is the gap this lesson is built to close.

Team, this note is about Tens and Ones, a short lesson from the Grade 1 Mathematics course. It takes about 15 minutes. The objective is written in kid language, and I like it for that reason: “I can count groups of ten and extra ones.” Every first grader can repeat that sentence back to you, which makes it easy to check whether they can actually do it.

What the lesson asks students to do

The work is simple to describe and harder to master. Students count a quantity by making groups of ten, then count the extra ones that do not fill another group. From there the lesson connects those two counts to the two digits of a number. The digit on the left tells how many tens. The digit on the right tells how many ones left over. That is the whole idea, and it is a big one for six-year-olds who have spent most of kindergarten counting by ones.

The standard behind it is CA.MATH.1.NBT.2, part of the California Common Core State Standards for mathematics, in the Number and Operations in Base Ten domain under the cluster called Understand place value. It asks first graders to understand that the two digits of a two-digit number stand for amounts of tens and ones. California added a line to the national version, and honestly the California addition is the part I would pin above your desk: students should compose and decompose two-digit numbers using tens and ones, with concrete models and drawings to reinforce the idea. In plain terms, they should be able to build a number from tens and ones and also take a number apart into tens and ones, and they should do it with their hands and their pencils before they do it in their heads.

This is the same standard first grade teachers work on in Oakland Unified, Capistrano Unified, Compton Unified and Glendora Unified, and in every other district in the state, so a student who moves mid-year is landing in the same expectation.

What to listen for while they work

The most useful thing you can do during this lesson is listen to how students count. A few patterns tell you a lot.

Listen for the student who makes a group of ten and then counts the whole group again by ones. That child has done the physical step without trusting it yet. They are not wrong, they are just not there, and they need more reps grouping and naming the group as one ten.

Listen for the student who can say three tens and four ones but cannot tell you that three tens is thirty. That is a vocabulary connection that has not been made. Ask them to count the tens out loud, ten, twenty, thirty, and watch what happens.

Listen for numbers with nothing in the ones place. I would test a few of my own after the lesson, like 40 or 70, because the zero trips up a lot of kids. A student who understands that 40 means four tens and no extra ones has the concept. A student who tries to show a zero with a cube has not.

Here is my honest caveat. Fifteen minutes on a screen is an introduction, not the whole job. The California language about concrete models and drawings is there for a reason, and I would not count on the lesson alone to make the idea stick. Plan for cubes, ten-frames or quick sketches of sticks and dots right after it.

Folding it into the week

My suggestion for the team: use it as a whole-class launch early in the week, with everyone watching and answering together, then spend the next couple of days building and drawing numbers in small groups. The lesson gives everyone the same language, groups of ten and extra ones, and that shared language makes your small-group time move faster.

It also works well for a student who missed the week. If someone was out when you introduced place value, this first grade place value lesson lets them catch the core idea in a short sitting before they rejoin the class at the tables.

For intervention, it is a good fit for the kids you flagged during your listening. Pull a group of three or four, run through the lesson together, and stop after each example to have them build the same number with cubes. Short lesson, short group, lots of hands on materials.

One more thing to try before Friday: give each student a two-digit number and ask them to show it two ways, once with cubes and once as a drawing. If the drawing has the right number of tens and the right number of ones, you will know the digits finally mean something to them.