Once numbers grow past ten, counting and seeing at a glance aren't enough. We need a building block that shows both how big a number is and exactly which number it is. Tens and ones is that block.
The goal here is a habit of building and noticing: making a number from tens and ones, and seeing that same number in more than one way, as rows on a hundred square, as blocks on the table, as two digits.
A child who builds a number rather than just writing it starts to notice how its parts fit together. That noticing, little and often, is what you're growing.
Once we start to look at larger numbers, our building blocks have to do more. Now they must hold two things at once: magnitude (how big) and accuracy (exactly which number). Tens and ones are the introduction to this. These blocks stop the structure hiding behind the digits and make you see it and build it, whether as rows on a hundred square or as tens-and-ones blocks you can hold.
Being secure here matters far beyond two-digit numbers: it is what later makes decimal fractions and very large numbers feel manageable rather than mysterious. And as your child plays, what they notice, and what they don't yet, tells you exactly where to go next with these vital tools.
Use the arrows to set the tens and the ones, and watch the number fill the hundred square.
Free games and activities for building with tens and ones, a few playful minutes at a time.
A hundred-square poster, number stickers and tens-and-ones blocks, so your child can build numbers on the table, not just the screen.