JCE Home Economics cheat sheet

Macronutrient energy values: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g.

Basal metabolic rate (BMR) is measured 12–14 hours after the last meal, at rest, at thermoneutral temperature; it typically accounts for 60–70% of total daily energy expenditure.

Harris–Benedict (revised Mifflin–St Jeor) equations estimate resting energy expenditure; multiply by an activity factor (1.2 sedentary to 1.9 very active) for total needs.

The six nutrient classes are carbohydrate, protein, fat, vitamins, minerals and water; only the first three are energy-yielding.

Protein complementation pairs limiting amino acids: cereal (limiting lysine) with legumes (limiting methionine) gives a complete amino acid profile.

Fat-soluble vitamins A, D, E and K require bile and dietary fat for absorption; water-soluble B-complex and C are not stored in large amounts and excess is excreted.

Glycaemic index ranks carbohydrate foods by postprandial blood glucose response; low-GI foods (≤55) produce slower, flatter glucose curves.

Danger-zone rule: keep perishable food out of the 5–60 °C range; bacteria multiply fastest between 20–45 °C, and the 2-hour rule limits time in the danger zone.

Deficiency markers: vitamin C → scurvy; vitamin D → rickets/osteomalacia; iron → microcytic anaemia; iodine → goitre; thiamin → beriberi.

Management process cycle: planning → organising → implementing (directing) → controlling/evaluating; resources are human (time, energy, skills) and non-human (money, equipment, space).

Opportunity cost: the value of the next-best alternative forgone when a resource is allocated to one use.

The family life cycle stages (beginning, childbearing, childrearing, launching, aging) shift spending patterns and space needs at each transition.

Budget rule of thumb: fixed expenses (rent, insurance) plus flexible expenses (food, utilities) plus discretionary spending should be balanced against net (take-home) income, not gross.

Time-management tools include the Pareto principle (roughly 80% of results from 20% of tasks), priority matrices (urgent vs important) and standardised work routines.

Work simplification applies motion economy: combine tasks, rearrange work centres, eliminate unnecessary steps, and use labour-saving equipment.

Consumer protection mechanisms: warranties (express vs implied), cooling-off periods, and complaint escalation from retailer to manufacturer to consumer protection body.

Conflict resolution in families uses negotiation and compromise; win–win outcomes preserve relationships better than win–lose outcomes.

Developmental domains: physical/motor, cognitive, language, social-emotional; milestones are ranges, not fixed deadlines, and vary with individual and cultural context.

Gross motor sequence: head control (2–3 months), rolling (4–6), sitting unsupported (6–8), crawling (8–10), standing with support (9–12), walking (12–15 months).

Object permanence (Piaget, sensorimotor stage, roughly 8–12 months): the understanding that objects continue to exist when out of sight.

Piaget's stages: sensorimotor (0–2), preoperational (2–7), concrete operational (7–11), formal operational (11+).

Erikson's psychosocial stages: trust vs mistrust (0–1), autonomy vs shame (1–3), initiative vs guilt (3–6), industry vs inferiority (6–12).

Attachment: secure, avoidant, ambivalent and disorganised patterns; secure attachment develops through consistent, responsive caregiving.

Language development: cooing (2–3 months), babbling (6 months), first words (about 12 months), two-word phrases (18–24 months), telegraphic speech (2 years).

Safety rules: back-to-sleep for infants reduces SIDS risk; childproofing begins at crawling; choking hazards include whole nuts, grapes and small toys under 3 years.