M.1-Arithmetic, standard form and significant figures

Use decimal and standard form notation, calculators, means, powers, roots, trigonometric functions, justified significant figures and approximations to check calculated magnitudes.

Use m.1-arithmetic, standard form and significant figures to connect the rule to the data and decision in the question.

This matters because m.1-arithmetic, standard form and significant figures determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply m.1-arithmetic, standard form and significant figures to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: M.1-Arithmetic, standard form and significant figures is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.