Basic Math Study Guide

Written by Raul Barrea

I'm the Physics Sensei

September 15, 2025

🥋 Basic Math – White to Black Belt Mastery

Intro Quote

“Strong foundations build unshakable strength.”


White Belt – Key Concept

Basic math is the language of physics.
It gives you the tools to measure, compare, and solve problems.

Core skills include:

  • Addition and subtraction
  • Multiplication and division
  • Exponents and roots
  • Order of operations

Core Principles

  1. Numbers represent quantities we measure.
  2. Operations follow a set order: parentheses, exponents, multiplication/division, addition/subtraction (PEMDAS).
  3. Negative numbers and fractions follow the same rules.
  4. Rounding and significant figures show the precision of data.
  5. Units must always be carried through calculations.

Key Equations (SI Units)

  • a + b = c (addition)
  • a − b = c (subtraction)
  • a × b = c (multiplication)
  • a ÷ b = c (division)
  • √a = b (square root)
  • aⁿ = result of exponentiation

Symbols:

  • a, b, c = numbers or measured values
  • n = power or exponent

Common Mistakes and Pitfalls

  • Ignoring the order of operations.
  • Dropping negative signs.
  • Forgetting units.
  • Rounding too early (wait until the final step).
  • Mixing up square roots and squares.

🥋 Sensei’s Shortcuts

  • Always solve parentheses first.
  • Write out every step, even simple ones.
  • Carry units with your numbers.
  • Round at the very end, not in the middle.

Worked Example – Step by Step (White Belt)

Problem:
Calculate (8 + 4 × 2)².

Step 1. Order of operations
Inside parentheses: 4 × 2 = 8 → (8 + 8)²

Step 2. Simplify
= (16)²

Step 3. Final Answer
= 256


Practice Drill (with answers)

  1. (6 + 2 × 3)² = ?
    • Answer: 100
  2. √(81 ÷ 9) = ?
    • Answer: 3

Yellow Belt Extension – Deeper Skills

Problem:
A student multiplies 2.5 × 3.40. Show the answer with correct significant figures.

Solution Outline:

  • Multiply: 2.5 × 3.40 = 8.50
  • Least number of significant figures: 2 (from 2.5)
  • Final Answer: 8.5

Extra Practice:
Round 123.456 to 3 significant figures.

  • Answer: 123

Black Belt Mastery – Exam Strategy and Challenge

Problem:
A measurement is recorded as 5.6789 m. You must use it in the calculation: (5.6789 × 2.13) ÷ √3.00. Report the answer with proper significant figures.

Solution:

  1. Multiply: 5.6789 × 2.13 = 12.1
  2. Divide: 12.1 ÷ √3.00 = 12.1 ÷ 1.73 = 7.00
  3. Significant figures:
    • 5.6789 has 5 sig figs
    • 2.13 has 3 sig figs
    • 3.00 has 3 sig figs
      → Final Answer should have 3 sig figs

Final Answer:
7.00 m


Sensei’s Final Words

“Math is not the obstacle — it is the training ground for your mind.”

You May Also Like…

Circular Motion and Centripetal Force

Circular motion happens when an object travels around a circle at constant speed.
Even if speed stays the same, the direction changes, so there is acceleration.

That inward acceleration is called centripetal acceleration, caused by a centripetal force.

In simple words: Circles need inward pull.

Work and Energy

Work and energy describe how forces cause motion and how motion is stored in different forms.

Work transfers energy.

Kinetic energy is energy of motion.

Potential energy is stored energy due to position.

The work-energy theorem says: Work = change in kinetic energy.

Kinematics in Two Dimensions

Kinematics in Two Dimensions

In 2D motion, movement is split into horizontal and vertical components. These act independently, connected only by time. If you need a refresher on splitting vectors into x and y, review the Vectors Study Guide.

0 Comments