how many pieces an object has when it has been cut in half. asks innumerable questions: why? what? where? when? how? who? eager to learn new things. curious and inquisitive. language development vocabulary of 1,500 words plus. tells a familiar story while looking at pictures in a book. defines simple words by function: a ball is to bounce; a bed is to sleep in. identifies and names four to eight colours. recognizes the humor in simple jokes; makes up jokes and riddles. produces sentences with five to seven words; much longer sentences are not unusual. states the name of own city or town, birthday, and parents' names. answers telephone appropriately; calls person to phone or takes a brief message speech is almost entirely grammatically correct. uses "would" and "could" appropriately. uses past tense of irregular verbs consistently: "went", "caught", "swam." uses past-tense inflection (-ed) appropriately to mark regular verbs: "jumped", "rained", "washed". social development enjoys and often has one or two focus friendships. plays cooperatively (can lapse), is generous, takes turns, shares toys. participates in group play and shared activities with other children; suggests imaginative and elaborate play ideas. shows affection and caring towards others especially those "below" them or in pain generally subservient to parent or caregiver requests. needs comfort and reassurance from adults but is less open to comfort. has better self-control over swings of emotions. likes entertaining people and making them laugh. enjoys conversing with other people. boasts about accomplishments. often has an imaginary friend six-year-old physical weight gains reflect significant increases in muscle mass. heart rate and respiratory rates are close to adults. body may appear lanky as through period of rapid growth. baby teeth beginning to be replaced by permanent ones, starting with the two lower front teeth 20/20 eyesight; if below 20/40 should see a professional. the most common vision problem during middle childhood is myopia, or nearsightedness. uses 6,700 to 7,100 kj (1,600 to 1,700 kcal) a day. motor development gains greater control over large and fine motor skills; movements are more precise and deliberate, though some clumsiness persists. enjoys vigorous running, jumping, climbing, and throwing etc. has trouble staying still. span of attention increases; works at tasks for longer periods of time. can concentrate effort but not always consistently. understands time (today, tomorrow, yesterday) and simple motion (some things go faster than others). recognizes seasons and major activities done at certain times. has fun with problem solving and sorting activities like stacking, puzzles, and mazes enjoys the challenge of puzzles, counting and sorting activities, paper-and-pencil mazes, and games that involve matching letters and words with pictures. recognizes some words by sight; attempts to sound out words in some cases the child may be reading well. functioning which facilitates learning to ride a bicycle, swim, swing a bat, or kick a ball. enjoys making things. reverses or confuses certain letters: b/d, p/g, g/q, t/f. able to trace objects. folds and cuts paper into simple shapes. can tie laces, string (like shoes). language can identify right and left hands fairly consistently. holds onto positive beliefs involving the unexplainable (magic or fantasy) arrives at some understanding about death and dying; expresses fear that parents may die. talks a lot. loves telling jokes and riddles; often, the humor is far from subtle. experiments with slang and profanity and finds it funny. enthusiastic and inquisitive about surroundings and everyday events. able to carry on adult-like conversations; asks many questions. learns 5 to 10 words a day; vocabulary of 10,000–14,000. uses appropriate verb tenses, word order, and sentence structure. social and emotional uses language rather than tantrums or physical aggression to express displeasure: "that's mine! give it back, you dummy." talks self through steps required in simple problem-solving situations (though the "logic" may be unclear to adults). has mood swings towards primary caregiver depending on the day friendship with parent is less depended on but still needs closeness and nurturing. anxious to please; needs and seeks adult approval, reassurance, and praise; may complain excessively about minor hurts to gain more attention. often cannot view the world from another's point of view self-perceived failure can make the child easily disappointed and frustrated. cannot handle things not going their own way does not understand ethical behavior or moral standards especially when doing things that have not been given rules understands when he or she has been thought to be "bad"; values are based on others' enforced values. may be increasingly fearful of the unknown like things in the dark, noises, and animals. seven-year-old motor development well-developed hand-eye coordination good sense of balance capable of basic gymnastics moves such as somersaults writing grips the dynamic tripod grip is the final stage of holding writing implements language vocabulary now numbers at least a few thousand words capable of telling time begins to understand how sounds form words social and emotional highly self-critical and eager to please can understand right and wrong increased ability at problem solving and reasoning can feel shame and guilt complains a lot and has strong emotional swings occasionally has meltdowns over minor frustrations, mainly for attention ability to deal with mistakes and failure improves beginning of sexual attraction to/interest in peers explore genitalia with other children their age. this occurrence typically begins with children "playing doctor" or who say "show me yours and i'll show mine." the event is the child showing interest in "naughty parts" which are perceived as forbidden reluctant to undress in front of others and wish to have more privacy from parents eight-year-old motor development has good finger control increased physical strength and endurance almost able to converse at an adult level wants to understand how and why things work clear, logical thinking skills exhibits a clear preference for certain subjects and activities language skills enjoys reading can start to understand how opposites work can now speak clearly social and emotional starts to develop a close circle of same-gender friends becomes more susceptible to peer pressure enjoys group activities prone to mood swings and melodramatics extremely impatient and may have a hard time waiting for special events preteen/late childhood years nine-year-old motor skills quite good at handling tools manual dexterity and hand-eye coordination are well-developed capable of drawing in detail may persist with a particular physical activity to the point of exhaustion language skills good at memorizing and recalling information, but typically does not show a deep understanding of it capable of concentrating and resuming a task after an interruption eager to learn skills starts to understand right vs wrong in place of good vs bad social skills often displays an intense revulsion of the opposite gender will use physical complaints as a means of getting out of undesired tasks generally dependable and can be trusted with basic responsibilities prone to wide mood swings ten-year-old motor skills capable of demanding motor/endurance tasks like bicycling and team sports some girls may begin puberty, starting with breast development and followed by a change in facial shape adult-like motor planning motor planning includes an individual's choice of movements and trajectory of such movements. children begin to display motor planning in preference of certain body parts such as hand preference. for instance, left-handed children will start to plan how they can perform a motor skill, like throwing a ball, but execute it with their left hand. the preferred hand selection of children would also be displayed in other motor tasks. children show significant increase in sensitivity to end-state comfort (esc) esc is the preference to initially use unusual uncomfortable postures and movements to end in a comfortable position. one common method of studying end-state comfort is the task of over-turned glass. in this task, individuals are asked to use one hand to pick up a drinking glass that is placed up-side down, turn it upright, and pour water from a given cup into the glass. once the children begins to grab the upside-down glass with thumb pointing down, then they have displayed end-state comfort. as a result, once they have turned over the glass, the child would have ended with palm holding the glass in a comfortable position. the number of grips conforming to esc strongly increased with age. language skills still does not display a deep understanding of subjects does not yet fully understand right from wrong not yet good at organizing or planning things in a practical way social skills some sexual attraction to/interest in peers not as moody as 7- to 9-year-olds; overall disposition tends to be cheerful and fun-oriented friendships are highly important, with friends usually of the same gender. this is not consistent to every individual, nor important overall can have a short temper, but has learned to adjust anger levels according to the appropriateness of the situation gets along well with parents, eager to please has fewer fears than at younger ages eleven-year-old motor skills extremely jumpy and has a hard time sitting still girls typically begin breast development and growth of pubic hair; usually no puberty in boys rapid height gains better ability at making decisions begins to understand that not everyone holds the same beliefs early acne is common in girls language skills able to use logic and debate others quite well school reports may combine visual, oral, and written material social and emotional development often critical of others, stubborn, and egotistical tends to display anger physically by hitting people/objects, throwing things, or slamming doors friends are important, but with more arguments than before may be worrisome and afraid of things caring about what others think is more common twelve-year-old motor skills usually a substantial appetite most girls are developing breasts, filled-out pubic hair, fine underarm hair, and may begin menstruation puberty normally begins for boys at this age with enlargement of the testicles and later the penis along with the growth of fine pubic hair and frequent, random erections language skills capable of categorizing information to make better sense of it reads adult books and magazines on subjects of interest capable of proofreading homework for spelling, grammar, and logic social skills overall disposition is pleasant and upbeat can become extremely excited over subjects of interest or accomplishments strongly prone to peer pressure and following trends more stable friendships with fewer melodramatics than at 11 may begin to have sexual attraction to/interest in peers teenaged years thirteen-year-old menstruation in girls is common growth spurts, ejaculations and voice changes are common in boys, as well as "peach fuzz", small strands of facial hair above their lip along with fine underarm hair moody and uncomfortable with themselves and their surroundings likes to be alone and values privacy may believe the world is out to get them insecure about their bodies may not get along well with adults fourteen-year-old boys may begin growth of fine facial hair generally pleasant, sunny disposition often a high interest in extracurricular activities may want to please and be popular has a large circle of both-gender friends may show signs of depression fifteen-year-old typically quarrelsome and unwilling to share their problems with others may want to be independent and free of their family typically gets along better with siblings than parents friendships are highly important romantic interests are common sixteen-year-old boys typically begin to grow thick facial hair good overall relationship with family begins to see parents as human beings instead of authority figures friendships highly important, may have a wide circle of both gender friends seventeen-year-old most teens have reached sexual maturity sexual intercourse is more common romantic interests are more common love interests can be intense