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Apply a Newly Defined Operation

A new symbol or rule is defined, and the task is to evaluate or solve by substituting carefully into that definition and respecting order of operations. Learners meet symbol-coded equations they solve in order, then defined operators over whole numbers and fractions. The skill is reading a rule precisely and executing it. A function rule such as f(a + b) = f(a) + f(b) is the grade-8 form: plug in the inputs the rule makes easy and build outward.

grade 2–8 FractionsOperationsFunctionsExpressions Convert to AlgebraIdentify Subproblems

Builds on: Multiplication as Equal Groups

Progression (11)

g3 1. Solve shape-coded products in order Operations · foundational
g3 2. Evaluate a custom-defined operation symbol Operations · core
g3 3. Set up an expression and compute in order Operations · core
g5 4. A new symbol can define a custom operation Operations · core
g4 5. Apply a defined symbol to compute with fractions Fractions · advanced
g5 6. Evaluate a newly defined operation symbol Operations · core
g5 7. Define a custom operator and evaluate it Operations · advanced
g7 8. Peel a nested defined operation from the outside Expressions · advanced
g8 9. Find the x that makes the input right FunctionsExpressions · advanced
g8 10. Build values up from the sum rule FunctionsExpressions · advanced
g8 11. Plug special inputs into the identity FunctionsExpressions · advanced

Bridges to competition (5)

Reasoning problems that extend this idea toward competition:

Old multiplication methods Pattern & rule → Branching State Enumeration
Convert ancient symbol numerals Pattern & rule → Arithmetic Expression Decomposition
Discover the hidden operation rule Pattern & rule → Arithmetic Expression Decomposition
Decode the shape-to-number rule Pattern & rule → Arithmetic Expression Decomposition
Apply a newly defined symbol rule Pattern & rule → Arithmetic Expression Decomposition

Leads to competition types: Arithmetic Expression DecompositionBranching State Enumeration