Workplace Mathematics 11

Interest rate, compounding frequency, and TIME drive growth — time is the amplifier ordinary savers control most.

A growth graph's curve tells the story: linear means simple interest, upward-bending means compounding.

Banking services carry costs and returns: account fees, e-transfer costs, and promotional rates all belong in the comparison.

Credit card interest compounds on the unpaid balance — minimum payments can stretch a small purchase into years of interest.

A vehicle costs more than its payment: insurance, fuel, maintenance, and depreciation ride along every month.

Slope = rise/run wears three outfits: a pitch ratio (4/12), a percent grade (6%), or an angle (tan⁻¹ of rise/run).

The angle of elevation connects slope to trigonometry: angle = tan⁻¹(rise/run).

Codes and specs set slope limits — accessibility ramps at most 1:12, stairs within a comfort range — so converting correctly is compliance, not decoration.

An interest rate is a percent change per time unit — 6%/yr changes a balance by 6% of itself each year.

Rates quoted per different periods must be aligned to compare: 1.5%/month is not 'less' than 12%/yr — it's 18%/yr.

Expected value = sum of (outcome × probability): a game with negative expected value loses money on average, every average.

The 'house edge' is a small negative expectation applied millions of times — the law of large numbers does the rest.

Insurance inverts the lottery: many pay small premiums; probability-priced payouts go to the unlucky few.

Every survey stat rides on its sample: who was asked, how many, and how they were chosen decide what it can claim.

Margin of error and confidence ('±3%, 19 times out of 20') are the honesty labels — a 2-point lead inside a 3-point margin is a tie.

Check the frame before the data: axis start, scale steps, time window, and what was left OUT of the graph.

Cherry-picked windows manufacture trends — the same series can rise or fall depending on where you start the clock.

Graphs drive real decisions — voting, buying, health choices — which is exactly why misleading ones are worth catching.

Orthographic views (top, front, side) capture a 3-D object in flat truth — each view holds true lengths for its plane.

An exploded diagram pulls parts apart along assembly lines — order and orientation ARE the instructions.

Perspective drawing trades measurement for realism: one- and two-point perspective converge to vanishing points.

A scale like 1:50 converts both ways — diagram × 50 = reality; reality ÷ 50 = diagram.

Angles survive scaling untouched: a 30° roof is 30° at any scale — only lengths shrink.