This page covers Arithmetic at the High School Advanced level, delivered as a proof walkthrough. The foundation of all mathematics. Four operations, place value, order of operations, and the mental. The material here corresponds to Grades 10–12 courses: Algebra 2 and Trigonometry.
This proof walkthrough covers Arithmetic at the High School Advanced level. The key skills addressed are Addition and subtraction, Multiplication and division, Order of operations (PEMDAS), Mental arithmetic, Estimation and rounding.
At this level, students are expected to bring High School Advanced prerequisites to each problem and to work with the degree of precision appropriate for High School Advanced courses. The worked examples here are written for students who know the basic definitions but need to see the reasoning at each step — not for complete beginners, and not for students who have already mastered the material.
How to use this page
Work through the example problem yourself before reading the solution. Identify where you get stuck. Then read the solution carefully, paying attention not just to the steps but to the decision at each step — why this operation and not another?
The connection to High School Advanced prerequisites
This material assumes familiarity with the prerequisites of Arithmetic. If any step in the solution refers to a technique you do not recognise, that is the gap to address first.
Worked Example
A standard arithmetic problem at the high school advanced level.
Work through step by step: identify what is given, what is asked, apply the relevant technique, and check your answer against the original conditions.
Confusing the order of operations: computing left-to-right without checking precedence. The rule is exponents before multiplication, multiplication before addition — not left-to-right.
Frequently Asked Questions
How is Arithmetic different at the HS Advanced level compared to earlier levels?
At the High School Advanced level, Arithmetic builds on Grades 10–12 prerequisites. Students are expected to have completed Algebra 2 before tackling this material.
Which exams test Arithmetic at this level?
SAT/ACT Math, GRE Quantitative, GMAT Quant.
What is the single most effective way to practise Arithmetic for HS Advanced students?
The most effective practice at the High School Advanced level is deliberate work on novel problem setups — not repeated drilling of the same template. Attempt problems before looking at solutions, and review errors by identifying the specific step where the reasoning broke down.