Unit price explained: compare packs, bulk deals and discounts
Find the better-value pack using one measurement basis, then account for discounts, delivery and waste.
Shopping
Shopping: Practical explanations, worked examples and calculators for everyday decisions.
Reverse sales tax: find the price before tax
Work backward from a tax-inclusive total using the correct formula, and distinguish removing tax from applying a discount.
Bulk discount or smaller pack: compare unit prices
Calculate the price per kilogram or item after coupons and multibuy offers, then decide whether a large package really saves money.
Stacked discounts and sales tax: find the final price
Calculate sequential promotions correctly and see why two discounts are not usually added together.
Price per serving versus price per 100 g: compare food packages
Compare package sizes fairly after accounting for edible yield, serving size and the unit printed on the shelf.
Percentage discount or fixed coupon: which deal is cheaper after shipping?
Compare offers by the final amount paid, including coupon rules, delivery charges and the tax treatment of discounts.
Dilute a brine by weight: use the total solution mass
Calculate added water from an existing salt solution and a lower target mass percentage without confusing water-only and solution-based ratios.
Fluid ounces and ounces: choose volume or mass before converting
Use the correct converter for fl oz and oz, and include density when changing between volume and mass.
Scale a bread recipe without changing hydration
Scale flour and water together, check baker’s percentages, and keep ingredient weights separate from volume measures.