Counting to 20
Turn on the lights on the string. See five, and five more!
For grown-ups
Your child turns on colored lights on a string. Tap a light and it turns on, together with every light before it, in one smooth move; tap a light that is on to turn it and the ones after it off. The first five lights on a string are warm coral and the next five are blue, so seven looks like "five and two more". Some turns ask how many lights are on; your child taps one of three big number cards.
A wrong number is never undone for your child: the voice says how many lights are on and what was asked. After a pause or two tries the screen dims around the group of five (or ten) so it stands out. A round is 6 numbers, then it stops.
Child lock: tap the lock at the top right. The ways out hide and the back button stays in the game. To unlock, hold the lock for 3 seconds and answer a sum.
Why it's good for your child, what they learn, and how we designed it
Free, no ads, no sign-in. We count plays without names or anything that identifies your child, and your child is never recorded. The lights are drawn in code, and they never blink or twinkle.
Why it's good for your child
The bead rack (rekenrek) is a classroom tool for one big reason: children see 7 as "5 and 2" instead of counting to 7. In a classroom study, students taught with a rekenrek scored much higher on adding and subtracting to 20 than students taught without one (ERIC EJ804513). Seeing small amounts at a glance is linked with learning counting and arithmetic more easily (Erikson Early Math, Didax).
What they learn
Seeing amounts up to 20 in groups of 5 and 10, breaking numbers into parts, making 10, doubles, and teen numbers as "ten and some more". These match kindergarten Common Core math K.CC.B.5, K.OA.A.3, K.OA.A.4 and K.NBT.A.1, with first steps toward 1.OA.C.6.
How we designed it for ages 4 to 7
One tap moves a whole group of lights, just like the one push on the real rack, so children see fives instead of counting dots. Lights glide and glow up slowly, one move at a time, then hold still (they never twinkle), and nothing loops, because fast, busy screens lowered 4-year-olds' attention and self-control right after (Lillard & Peterson 2011). A round is 6 numbers that ends on "All done", with nothing to collect and no "one more" prompt (Radesky 2022), and the voice names the parts your child made. A wrong number is never undone for them: the voice says how many lights are on and gives a small hint about the five, and the Child lock keeps leaving and settings with you.
About the game
Counting to 20 is a free counting game for children 4 to 7. It is built on the rekenrek, the bead rack many kindergarten and first grade classrooms use: strings of ten beads, each string in a group of five in one color and five in another. Here every bead is a light bulb on a string of lights, five warm coral and five blue. Lights that are on gather on the left, and the rest wait on the right. They glow softly and stay still: no blinking or twinkling.
The point of the rack is to see numbers instead of counting them one by one. Seven is a whole group of five and two more. Ten is two fives. Fourteen is a full string of ten and four more. When the lights turn on in groups, children start to know those amounts at a glance, which is the base for adding and taking away later.
How a round goes
Pick how far to count. Up to 5 has one short string for age 4: turn on one to five lights, and say how many are on. Up to 10 has a full string for age 5, and adds "make ten": some lights are on, and your child turns on more to fill the string. Up to 20 has two strings for ages 6 and 7, with teen numbers ("ten and four more"), doubles ("turn on three on each string") and how many up to twenty.
The voice asks for each number and names the parts when it's right ("Seven! Five and two more make seven."). A round is 6 numbers. Then the game stops on "All done" with a line for you to try together with your fingers, and the next round waits for a tap.
Before you hand over the phone, tap the lock at the top right. More: kindergarten games, preschool games, how we build calm games, questions.
Questions parents ask
Is Counting to 20 free?
Yes. There is no sign-in, nothing to download and nothing to buy inside the game. It runs in the web browser on phones, tablets and computers.
What ages is it for?
Ages 4 to 7. Up to 5 suits age 4, Up to 10 suits age 5, and Up to 20 (two strings, doubles and teen numbers) suits ages 6 and 7.
Why lights in groups of five?
It is the classroom bead rack, the rekenrek. The first five lights on each string are warm coral and the next five are blue, so a child sees seven as five and two more instead of counting one by one.
What happens when my child gets it wrong?
Nothing is undone and there is no buzzer. The voice says how many lights are on and what was asked. After a pause or two tries, the screen dims around the group of five or ten so it stands out.
How long is a round?
6 numbers, then the game stops on an All done screen with a line for you to talk about together. Nothing starts by itself.
All done!
Grown-up: