EXAMPLE 01A parent walkthrough
If f(x) = 2x² - 3, find f(4)
Show them: Substitute: 2(4)² - 3
Say: 4² = 16, so 2×16 - 3 = 29
Say: f(4) = 29
FINAL ANSWER
29
MATH LEVEL K
Functions — Level K Parent Guide
Last updated:
Functions, quadratic functions and their graphs, and inequalities.
Grade 11 · approximate gradeTHE DEFINITION
What is Kumon Math Level K?
Kumon Math Level K (Functions) is the 16th of 21 levels in the Kumon math program, where children learn functions, quadratic functions and their graphs, and inequalities. It typically aligns with grade 11 schoolwork, though Kumon places children by ability rather than age, so the grade is a guide, not a rule.
Level K builds directly on Math Level J: Advanced Quadratics and prepares children for Math Level L: Logarithms & Sequences. It is one of 21 Kumon math levels covered in this independent parent guide series.
This is an independent parent guide, not an official curriculum or placement assessment. Topics and pace can vary; your child’s instructor can confirm their current work.
- Evaluate f(x) for given x
- Graph parabolas
- Solve quadratic inequalities
- Find domain and range
- Apply graph transformations
How do I help my child with Level K?
Work through one example together, then let your child try the next one alone. A few small problems to try together — let your child attempt each first, then use these prompts when they need a nudge.
Original examples in Kumon style, written for parents — not scanned worksheets.
EXAMPLE 02A parent walkthrough
Solve: x² - 4 < 0
Show them: Factor: (x-2)(x+2) < 0
Say: Sign chart: negative between -2 and 2
Say: -2 < x < 2
FINAL ANSWER
-2 < x < 2
How can parents support Level K?
Short, calm, and daily beats long and pressured. These small habits make Level K stick — pick one and start tonight.
f(x) is just a fancy name for y
Parabolas: find the vertex first, everything follows
Inequalities need sign charts, not just solving
A LITTLE MORE CLARITY