Understand the idea, practise it, then check your understanding. These starter lessons are written for learners and teachers; they are not copied from commercial education websites. The library will grow subject by subject.
Starter lesson collection
Each lesson includes a plain-language explanation, an example or application, and a short check-your-understanding activity. Choose “Show answers” only after attempting the questions.
MATHEMATICS · NUMBER
1. Understanding fractions
A fraction describes equal parts of a whole. In 3/4, the numerator (3) counts the parts being considered and the denominator (4) tells us how many equal parts make the whole.
Equivalent fractions
Fractions are equivalent when they represent the same amount. Multiply or divide both numerator and denominator by the same non-zero number: 1/2 = 2/4 = 3/6.
Worked example: Simplify 12/18. The greatest common factor of 12 and 18 is 6. Divide both numbers by 6: 12/18 = 2/3.
Adding fractions
When denominators match, add the numerators and keep the denominator: 2/7 + 3/7 = 5/7. If denominators differ, first express the fractions using a common denominator.
Check: Simplify 15/20.
Correct answer: 3/4. Divide numerator and denominator by 5.
Check: 1/3 + 1/6 = ?
Correct answer: 1/2. Since 1/3 = 2/6, then 2/6 + 1/6 = 3/6 = 1/2.
Show answers
15/20 = 3/4; 1/3 + 1/6 = 1/2.
MATHEMATICS · ALGEBRA
2. Algebraic expressions and equations
Algebra uses letters to represent numbers. In 3x + 5, x is a variable, 3 is its coefficient, and 5 is a constant. An expression has no equality sign; an equation states that two quantities are equal.
Solve by keeping both sides balanced
Worked example: Solve 2x + 5 = 17. Subtract 5 from both sides: 2x = 12. Divide both sides by 2: x = 6. Check: 2(6) + 5 = 17.
Whatever operation you perform on one side of an equation, perform the same operation on the other side. This preserves equality.
Check: Solve 3x − 4 = 11.
Correct answer: x = 5. Add 4 to get 3x = 15, then divide by 3.
Show answers
x = 5.
ENGLISH · GRAMMAR
3. Parts of speech and sentence structure
Words perform different jobs in a sentence. A noun names a person, place, thing or idea; a verb expresses an action or state; an adjective describes a noun; and an adverb often modifies a verb, adjective or another adverb.
Example: “The careful student answered quickly.” Student is a noun; answered is a verb; careful is an adjective; quickly is an adverb.
Subject and predicate
The subject tells who or what the sentence is about. The predicate says something about the subject. In “The children played outside,” “The children” is the subject and “played outside” is the predicate.
A complete sentence normally expresses a complete thought and has a subject and a predicate. Begin sentences with a capital letter and use appropriate end punctuation.
Check: In “Ada carefully opened the box,” which word is the adverb?
Correct answer: carefully. It describes how Ada opened the box.
Show answers
“Carefully” is the adverb.
BIOLOGY · CELLS
4. The cell: the basic unit of life
A cell is the smallest structural and functional unit of a living organism. Some organisms consist of one cell; plants and animals are made of many cells specialised for different functions.
Important cell structures
Cell membrane: controls movement of substances into and out of the cell. Cytoplasm: jelly-like material where many chemical reactions occur. Nucleus: contains genetic material and helps control cell activities. Mitochondria: release usable energy through cellular respiration.
Plant cells typically have a cellulose cell wall, chloroplasts in photosynthetic cells, and a large permanent vacuole. Animal cells do not have a cellulose cell wall or chloroplasts.
Application: Root hair cells absorb water and mineral ions; their long extensions increase the surface area available for absorption.
Check: Which structure controls what enters and leaves a cell?
Correct answer: the cell membrane.
Show answers
The cell membrane regulates movement into and out of the cell.
PHYSICS · MOTION
5. Distance, speed and time
Distance is the total path travelled. Speed is distance travelled per unit time. Average speed = total distance ÷ total time. In SI units, distance is measured in metres (m), time in seconds (s), and speed in metres per second (m/s).
Worked example: A cyclist travels 150 metres in 30 seconds. Average speed = 150 ÷ 30 = 5 m/s.
Rearranging the formula gives distance = speed × time and time = distance ÷ speed. Always check that the units are consistent before calculating.
Speed tells how fast an object moves; velocity also includes direction. Acceleration describes the rate of change of velocity with time.
Check: A runner covers 400 m in 80 s. What is the average speed?
Correct answer: 5 m/s. Divide 400 m by 80 s.
Show answers
Average speed = 400 ÷ 80 = 5 m/s.
CHEMISTRY · ATOMIC STRUCTURE
6. Atoms and elements
An atom is the smallest unit of an element that retains that element's chemical identity. It contains a tiny nucleus surrounded by electrons. The nucleus contains positively charged protons and, in most atoms, uncharged neutrons. Electrons carry negative charge.
The atomic number is the number of protons in an atom's nucleus. In a neutral atom, the number of electrons equals the number of protons. The mass number is the total number of protons and neutrons.
Worked example: A neutral atom has atomic number 11 and mass number 23. It has 11 protons, 11 electrons and 23 − 11 = 12 neutrons.
Atoms of the same element have the same number of protons. Atoms may gain or lose electrons to form ions.
Check: An atom has 8 protons and mass number 16. How many neutrons does it have?
Correct answer: 8 neutrons (16 − 8).
Show answers
Neutrons = mass number − atomic number = 16 − 8 = 8.
ECONOMICS · MARKETS
7. Demand and supply
Demand is the quantity of a good consumers are willing and able to buy at different prices over a period. Other things being equal, a higher price usually leads to a lower quantity demanded. Supply is the quantity producers are willing and able to offer for sale; other things being equal, a higher price usually encourages a higher quantity supplied.
Demand can change because of income, tastes, population, expectations or the prices of related goods. Supply can change because of production costs, technology, taxes, weather or the number of sellers.
Market equilibrium: The equilibrium price is where quantity demanded equals quantity supplied. A shortage occurs when quantity demanded exceeds quantity supplied at the current price; a surplus occurs when quantity supplied exceeds quantity demanded.
Check: If buyers want more units than sellers offer at the current price, what exists?
Correct answer: a shortage (excess demand).
Show answers
A shortage, also called excess demand.
CIVIC EDUCATION · CITIZENSHIP
8. Rights, duties and responsible citizenship
Rights are freedoms or protections people are entitled to under applicable law. Duties and responsibilities are obligations people are expected to fulfil. Responsible citizenship means respecting other people's rights, obeying lawful rules, participating peacefully in community life and helping protect public property.
Examples of civic responsibilities include respecting the rights of others, paying legally required taxes, obeying traffic rules, keeping the environment clean and taking part in lawful civic processes. Rights and responsibilities should be understood with reference to Nigeria's Constitution and applicable laws.
Everyday example: Freedom of expression does not give a person permission to threaten others or knowingly make unlawful harmful statements. Rights operate alongside legal limits and the rights of other people.
Check: Which action best demonstrates responsible citizenship?
Correct answer: respecting others' rights and following lawful civic rules.
Show answers
Respecting other people's rights and following lawful civic rules.
COMPUTER STUDIES · DIGITAL SAFETY
9. Staying safe online
Digital safety means protecting your devices, accounts, identity and personal information when using the internet. Use long, unique passwords and, where available, multi-factor authentication. Do not share passwords or one-time verification codes with other people.
Phishing is an attempt to trick someone into revealing information or installing harmful software, often through fake messages or websites. Be cautious of urgent threats, unexpected prizes, suspicious links and requests for secret information.
Safe habit: If a message claims your account will be closed unless you click a link immediately, open the official app or type the known website address yourself instead of following the message link.
Check: A stranger asks you to send the one-time code sent to your phone. What should you do?
Correct answer: do not share the code; verify the request through the service's official channel.
Show answers
Never share the code. Contact the service through its official app or website if you are unsure.
How this library will expand
The next content batches can add complete topic sequences, practical activities, diagrams, revision sheets and original examination-style questions. Curriculum alignment should be checked against the latest official Nigerian curriculum and each examination body's published syllabus. These starter lessons are foundational introductions, not a claim of complete syllabus coverage.