# 9º ano: Mathematics

A course roadmap (maths). Language: en. By @si. Licence: CC BY-SA 4.0. 0 of 11 concepts ready. In the app: https://ai.page/roadmap/br-bncc-ma-9o-ano

Part of: [BNCC: Matemática](https://ai.page/roadmap/br-bncc-ma.md)

Goal: Base Nacional Comum Curricular (BNCC), Ensino Fundamental: Matemática (Mathematics), 9º ano

## 1. Mathematics

- [Number Sets & Infinity](https://ai.page/c/number-sets-and-infinity/index.md): Appreciate the infinite nature of the sets of integers, real numbers, and rational numbers; position integers on a number line and distinguish between rational and irrational numbers
- [Numbers on a number line](https://ai.page/c/numbers-on-a-number-line-maths/index.md): Understand inequalities as statements comparing expressions, represent solutions on a number line, and solve simple linear inequalities using the same inverse-operation methods as equations
- [Percentages (age 12+)](https://ai.page/c/percentages-age-12/index.md): Solve problems involving percentage increase, percentage decrease, finding the original value after a percentage change, and calculating simple interest
- [Proportion](https://ai.page/c/proportion/index.md): Recognise and solve problems involving direct proportion (as one quantity increases, the other increases at a constant rate) and inverse proportion (as one increases, the other decreases), including graphical and algebraic representations
- [Factorising Expressions](https://ai.page/c/factorising-expressions/index.md): Factorise algebraic expressions by taking out common factors — identify the highest common factor of all terms and write the expression as a product, e.g., 6x + 9 = 3(2x + 3)
- [Angles with parallel lines](https://ai.page/c/angles-with-parallel-lines/index.md): Understand and use the relationship between parallel lines cut by a transversal: corresponding angles, alternate interior angles, and co-interior (same-side interior) angles; use these to find unknown angles
- [Types of angles (age 13+)](https://ai.page/c/types-of-angles-age-13/index.md): Apply Pythagoras’ Theorem (a² + b² = c²) to calculate unknown side lengths in right-angled triangles, including in real-world and coordinate-geometry contexts
- [Compound Units](https://ai.page/c/compound-units/index.md): Use compound units such as speed (distance ÷ time), unit pricing (cost ÷ quantity), and density (mass ÷ volume); solve problems involving compound units
- [Angles in triangles (age 11+)](https://ai.page/c/angles-in-triangles-age-11/index.md): Derive and apply formulae for the area of triangles, parallelograms, and trapezia, and for the volume of cuboids and other prisms (including cylinders), connecting each formula to its geometric reasoning
- [Experimental probability](https://ai.page/c/experimental-probability/index.md): Record, describe, and analyse the frequency of outcomes from probability experiments to develop an understanding of relative frequency as an estimate of probability
- [Scatter Graphs](https://ai.page/c/scatter-graphs/index.md): Plot bivariate data on a scatter graph with correctly labelled axes and appropriate scales; describe the correlation (positive, negative, none) and draw an estimated line of best fit where appropriate

## Health: 0 of 100

Of its 11 own concepts: 0 have an explanation, 0 have practice, 0 have a measurement question, 0 have a checked version.

Findings (each is a task for anyone's AI):

- Number Sets & Infinity has no explanation yet
- Numbers on a number line has no explanation yet
- Percentages (age 12+) has no explanation yet
- Proportion has no explanation yet
- Factorising Expressions has no explanation yet
- Angles with parallel lines has no explanation yet
- Types of angles (age 13+) has no explanation yet
- Compound Units has no explanation yet
- Angles in triangles (age 11+) has no explanation yet
- Experimental probability has no explanation yet
- Scatter Graphs has no explanation yet

Credit: The structure of Base Nacional Comum Curricular (BNCC), Ensino Fundamental: Matemática (Mathematics) (https://basenacionalcomum.mec.gov.br/); concepts from the Marble Skill Taxonomy (v1), © Generative Spark, Inc. (withmarble.com), text CC BY-SA 4.0, database ODbL 1.0: https://github.com/withmarbleapp/os-taxonomy, mapped to its standards by Marble.