Topic 2
Addition & Subtraction
Step 1 · Learn
Read the ideas
- 📖Free
Story Translators
Decide which way a story moves before you work out any numbers.
- 🐸Free
The Hopping Map
Add or subtract huge numbers by hopping one safe step at a time.
- 🔨Free
Number Smashers
Split by place value, then add the matching pieces or take the chunks away in stages.
- 🧱Free
The Column Stack
Carry and borrow your way through columns full of empty rooms.
- 🔍Free
The Missing Piece
Find a hidden number by asking whether the start or a part is missing.
- ⏪Free
The Rewind Button
Use the opposite operation to prove your answer is right.
- 🔮Free
Estimate & Check
4,812 + 3,197 ≈ 5,000 + 3,000 = 8,000.
Step 2 · Practice
Try the quests
Step 3 · Boss Battle
Beat the boss
🛡️ 🛡️ 🛡️ 3 shields — lose all → 60-second cooldown
Round 1
Your shield holds 25,000 units. Two verified power cells can boost it: the Blue Cell adds 12,500 units and the Green Cell adds 17,500 units. A third cell, the Red Cell, is flashing UNVERIFIED. GLITCH corrupted it, so do NOT count it.Your shield holds 25,000 units. Two…
FreeRound 2
The fuel gauge claims: 54,800 - 12,300 = 41,500 units left. That doesn't look right. Hit the Rewind Button (the inverse operation) to check GLITCH's maths.The fuel gauge claims: 54,800 - 12,300 =…
FreeRound 3
You have three reactor cores. • Core Red provides 34,250 units. • Core Blue provides exactly 2,000 MORE units than Core Red. • Core Yellow is offline and its value is unknown!You have three reactor cores. • Core Red…
FreeRound 4
You start at coordinate 38,200. The flight plan is: hop forward 14,500, then back 8,750, then forward 6,050.You start at coordinate 38,200. The…
FreeRound 5
The reserve tank was filled to exactly 80,000 units. GLITCH's siphon drained 46,275 units before you cut the line.The reserve tank was filled to exactly…
FreeRound 6
Three thrusters fire together. Thruster A delivers 28,400 units. Thruster B delivers exactly (2 × Thruster A − 6,800) units. Thruster C must deliver the missing amount to reach a 100,000-unit total surge.Three thrusters fire together. Thruster…
FreeRound 7
A ledger claims 5,090 + 2,880 = 970.A ledger claims 5,090 + 2,880 = 970.
Free