You're an archaeologist decoding an ancient crypt. Every door is sealed by a balance equation — keep both sides equal, isolate the mystery value, and the tombs open.
An equation is a balance: the two sides are equal. To find the mystery value, do the same thing to both sides until the variable stands alone. Whatever you remove from one side, remove from the other — the balance must hold.
The left pan holds the mystery box 📦 (x) plus 5 weights; the right holds 12. Remove weights from both sides equally to keep it level until the box stands alone.
The builders left a clue: "Three times the sealed number, plus four, equals twenty-five." Write the equation, then solve it in one try to open the vault.
Grounded in CA CCSS-M, Grade 6 · 6.EE (writing & solving one-step and two-step equations, keeping equations balanced). Part of the 4-D series.