Count the Reactor Lights: Free Kindergarten Counting and Comparing

Six beams block the hatch and every one of them is studded with lights. The instruction changes each time — cut every beam with more than five lights, or every beam with fewer — so a kindergartner has to count each cluster accurately and then decide whether that count clears the bar. It is counting and comparing in one move, which is closer to how counting is really used than reciting to twenty ever is. Get it wrong and the beam stays lit.

🚀 Try five now — free Or solve the whole Kindergarten case

What this station asks for

🔋 Count the LightsSparking light-beams are blocking the power panel! Count the little lights on each beam, then tap only the beams the panel asks for. Careful counting, Cadet! You read every beam, then cut only the ones the rule allows. Five tasks, then a snack wrapper goes into the Case File.

Five questions it might ask

Drawn from the same pool the activity uses, so these are the real thing rather than an illustration. The numbers change on every attempt — there is no fixed set to memorize.

Question	Answer
Count the lights — cut every beam with FEWER than 5 lights	●●●●, ●, ●●● (3 of 6 beams)
Count the lights — cut every beam with MORE than 5 lights	●●●●●●●●, ●●●●●●●, ●●●●●● (3 of 6 beams)

👀 What to watch for

Accurate counting and confident comparing are two separate skills, and children often have one without the other. If a child counts a beam correctly and then still cuts it, the counting is fine — it's "more than five" that hasn't landed yet. Try comparing two beams side by side before returning to the rule.

The Common Core standard behind it

Official wording, quoted in full — not our summary of it:

K.CC.B.5	Count to answer "how many?" questions about as many as 20 things arranged in a line, a rectangular array, or a circle, or as many as 10 things in a scattered configuration; given a number from 1—20, count out that many objects.

More about K.CC.B.5 and everything on this site that practices it →

🎉

For parents & teachers: unlock all the Kindergarten mysteries — Family $29/yr · Classroom $49/yr, per-standard Common Core progress tracking included.

⭐ Unlock everything →

Other Kindergarten skills in this case

Addition within 10K.OA.A.2 Subtraction within 10K.OA.A.2 Fluency within 5K.OA.A.5

All grades

About · Contact · Privacy · Number Cadets