A soot forge, three clay kilns, and a slate of two- or three-digit addition. Pour both place digits into the current kiln. If the melt hits ten or more, skim a ten to the next kiln. If it stays under ten, stamp the digit. Work ones, then tens, then hundreds. Built for third-grade multi-digit addition.
Read the Slate
A vertical problem such as 243 + 98 sits on the slate. Start at the ones kiln on the right.
Pour Both Ingots
Tap each glowing ingot. 3 and 8 pour into ones. A carry pip already in the kiln counts too.
Skim or Stamp
Eleven or more? Skim a ten to tens, then the leftover digit stamps. Under ten? Stamp at once. A wrong move costs a coal.
Finish the Sum
Work tens, then hundreds if they appear. Three spent coals end the run. Chase a new best on each difficulty.
Pour the Place
Each column shows two ingots — the digits in that place. Tap both to pour them into the kiln, on top of any carry already sitting there.
Skim a Ten
When the kiln holds ten or more, skim. Ten units leave, and a carry pip lands on the next kiln to the left.
Stamp the Digit
When the kiln holds nine or fewer, stamp. That digit writes on the slate. Then the next place lights up.
Ones, Then Tens
Easy stays with two-digit addends. Medium mixes in a three-digit number. Hard uses two three-digit numbers and more carries.
Kiln Carry is a third-grade addition game. A forge holds three place-value kilns and a vertical two- or three-digit problem. The player pours each place's digits into the kiln, skims a ten when the melt reaches ten, and stamps the leftover digit. That is regrouping, shown as a pour instead of a worksheet.
Carry Is Visible
Ten units leave the kiln and land on the next place. Students see why a 1 appears above the tens digit.
Right to Left
Ones unlock first. Tens wait. That is the same order as paper column addition.
Instant Heat
A wrong skim or stamp flashes. There is no full-page check after every column.
Touch First
Ingots, skim, and stamp are large. Play sits under the forge, not on the kilns.
The ones place. Tap both ones ingots. Then skim if the kiln has ten or more, or stamp if it has nine or fewer.
A skim sends ten units to the next kiln on the left and leaves the leftover ones in this kiln. That leftover digit is what you write.
That is a miss. Eleven is one ten and one one. Skim first, then the kiln can stamp a 1.
The size of the addends and how often a carry appears. The pour-skim-stamp rule stays the same.
Second through fourth grade (about ages 7–10), when students learn two- and three-digit addition with regrouping. Stay on Easy for two-digit sums.

□ + □ = ?
Add the Ones: 3 + 8
Two-digit addends. Learn the carry.