Dev intern Leo writes the scoring code. The distributive property, exponents, and like terms keep the formulas correct and efficient.
Leo's combo bonus uses an exponent: 2Âŗ + 4. "Exponents come first in the order of operations," he reminded himself, "before adding."
2Âŗ + 4 = (2 Ã 2 Ã 2) + 4 = 8 + 4 = 12.
Why does Leo compute 2Âŗ before adding 4?
Evaluate 3² + 5.
A multiplier rule read 3(x + 4). Leo used the distributive property to rewrite it as an equivalent expression â multiply the 3 by each term inside.
3(x + 4) = 3¡x + 3¡4 = 3x + 12. (Check: at x = 5, both give 27.)
Use the distributive property to expand 4(n + 2). (Write it like 4n+8, no spaces.)
Why are 3(x + 4) and 3x + 12 called equivalent expressions?
A power score used the expression 2x² + 1. Leo evaluated it at x = 3, being careful to square before multiplying.
2x² + 1 at x = 3: first 3² = 9, then 2¡9 = 18, then 18 + 1 = 19.
Evaluate 3x² when x = 2.
Leo found two score parts: 2x + 3x. "These are like terms â same variable â so I can combine them into one," he said. A simpler expression runs faster.
2x + 3x = 5x. (At x = 4, that is 5 Ã 4 = 20.)
Evaluate the score expression 5x + 2 when x = 6.
Why can Leo combine 2x and 3x but not 2x and 3?
Optional academic frame: "Because ______, the expressions are ______; this matters because ______."
Leo writes 2(x + 3) + 4x. Expand and combine like terms into a single simplified expression, then evaluate it at x = 5. Explain each step. (Try it, then check with your teacher.)
| Category | 4 â Advanced | 3 â Proficient | 2 â Developing |
|---|---|---|---|
| Comprehension & inference | All analysis questions correct; explains equivalence & like terms | 2 of 3 correct | 1 correct |
| Multi-step math | All 4 Solve-It answers correct (exponent+order, distributive, evaluate x², evaluate) | 3 correct | 2 correct |
| Mathematical argument | Proves/explains with specific values; clear reasoning | Claim with some evidence | Little evidence |
Grading accepts 4n+8 with or without spaces; numeric answers in common formats.