Planned · Early addition

Cairn Add™

For ages 3 to 6 · Additive reasoning: combining quantities and seeing the parts inside a number.

Age 3Age 4Age 5Age 6

Illustration for Cairn Add

Putting numbers together, with blocks and number bonds, well before worksheets.

The science

Before formal addition, children learn that a number is made of parts: five is four and one, or three and two. Cairn Add builds on the bonds from Cairn Number, moving from combining two groups of objects, to counting on, to recalling small sums, in the order research lays out.

Early addition grows out of part-whole understanding and counting strategies, not memorization. Children move from counting all, to counting on from the larger number, to retrieving facts (Baroody, 2006; Carpenter et al., Cognitively Guided Instruction).

Number bonds and the ten-frame make the structure of small numbers visible, which supports flexible strategies over rote recall (National Research Council, 2009).

Cairn Add stays within ten, uses objects and bonds first, and only later asks for the answer without the blocks.

The research, cited
  1. Baroody, A. J. (2006). Why children have difficulties mastering the basic number combinations. Teaching Children Mathematics, 13(1), 22-31.
  2. National Research Council (2009). Mathematics Learning in Early Childhood. National Academies Press.
  3. Carpenter, T. P., et al. (2014). Children's Mathematics: Cognitively Guided Instruction (2nd ed.). Heinemann.

By age, and how to do it at home

Here is what is developing at each age, what Cairn Add does about it, and a way to build the same skill at home. The home column is the real point: even if your child never opens the app, you can do this. The best early learning has always been a parent and a child and a little knowing-what-to-try.

5years old
What's developing

Combines two small groups by counting them all, and knows a few bonds like 2 and 2.

What the game does

Join two groups of blocks within five, with the count said aloud and the bond shown.

Try this at home

Count snacks in two piles, then push them together: “three and two, how many now?”

6years old
What's developing

Counts on from the larger number and recalls some sums within ten.

What the game does

Number bonds to ten, counting on, and the first sums without the blocks.

Try this at home

Roll two dice and race to say the total. Real dice, real giggles, real adding.

No reviews yet, on purpose. When real children have actually played it, their reactions go here. We do not buy reviews, run review farms, or invent five-star quotes. That this is unusual tells you something about the rest of the shelf.
Cairn Add

In the workshop.

This game is on the bench, built one at a time and only shipped when it clears all six of our promises. The science and the at-home guide above work today, with or without the app. Want to know when it lands? hello@playcairn.com.

See the whole library

The pedagogy behind every Cairn game is written in plain language and cited. Questions, or a researcher who wants to argue with us? hello@playcairn.com.