This article provides a comprehensive guide and revision for JSS 1 students preparing for their second-term mathematics examination. It covers key topics such as estimation, approximation, addition and subtraction in base 5 numerals, multiplication of numbers in base 2 numerals, the use of symbols, simplification of algebraic expressions, and solving simple equations. By the end of this article, students should have a clear understanding of each topic and be able to approach the questions with confidence.
1. Estimation
Estimation is the process of finding an approximate value rather than an exact number. It is useful when a quick, rough answer is needed and is commonly used in everyday life, such as when shopping or cooking. To estimate, we round numbers to the nearest ten, hundred, thousand, etc.
Key Concepts:
- Rounding: This involves approximating a number to a specific place value (e.g., nearest ten, hundred, etc.).
- Estimating sums or differences: We round the numbers to the nearest ten, hundred, or thousand and then add or subtract.
Example:
- Estimate the sum of 158 and 276 by rounding both numbers to the nearest hundred. 158 becomes 200, and 276 becomes 300. Now, 200 + 300 = 500.
Likely Questions:
- Round 362 to the nearest ten.
- Estimate the difference between 842 and 596.
- If you estimate the sum of 763 and 438, what is your answer?
- Round 8324 to the nearest hundred.
- Estimate the product of 46 and 59.
- Round 4876 to the nearest thousand.
- How do you estimate the quotient of 698 divided by 45?
- If you estimate the sum of 1225 and 347, what is your answer?
- Round 576 to the nearest ten thousand.
- Estimate the product of 23 and 92.
2. Approximation
Approximation is closely related to estimation but is used when you need a number that is close to the true value but easier to work with. In mathematics, approximation can also refer to finding the closest number within a certain margin of error.
Key Concepts:
- Decimal approximation: Rounding decimals to a specific place value.
- Approximating values for easier calculation: For example, using 3.14 for π.
Example:
- Approximate the value of π as 3.14 for calculations rather than using the full value of 3.14159.
Likely Questions:
- Approximate the value of 15.738 to two decimal places.
- What is the approximate value of π up to two decimal places?
- Round 0.759 to the nearest tenth.
- Estimate the sum of 6.97 and 5.81.
- Approximate the square root of 50 to the nearest whole number.
- Round 45.67 to the nearest hundredth.
- Approximate the value of 2.876 to the nearest whole number.
- Round 3.14159 to two decimal places.
- Estimate the difference between 9.68 and 4.23.
- Approximate 0.987 to the nearest tenth.
3. Addition and Subtraction of Numbers in Base 5 Numerals
In base 5, the digits used are 0, 1, 2, 3, and 4. The place values are powers of 5. When adding or subtracting numbers in base 5, you must carry over or borrow when you reach 5, just as you do with base 10.
Key Concepts:
- Base 5 place values: 1, 5, 25, 125, etc.
- Addition and subtraction rules: Add or subtract as you would in base 10, but carry over or borrow when you reach 5.
Example:
- To add 34 (base 5) and 21 (base 5), follow the base 5 addition rules.
Likely Questions:
- Add 13 (base 5) and 22 (base 5).
- Subtract 31 (base 5) from 44 (base 5).
- What is 42 (base 5) + 13 (base 5)?
- Subtract 30 (base 5) from 41 (base 5).
- Add 11 (base 5) and 14 (base 5).
- What is 23 (base 5) – 12 (base 5)?
- Add 4 (base 5) and 2 (base 5).
- Subtract 11 (base 5) from 33 (base 5).
- What is 21 (base 5) + 32 (base 5)?
- Subtract 14 (base 5) from 40 (base 5).
4. Multiplication of Numbers in Base 2 Numerals
Base 2, also known as binary, uses only the digits 0 and 1. Multiplying numbers in binary follows the same process as in base 10, but it uses only 0 and 1.
Key Concepts:
- Binary multiplication: The multiplication table for binary is simple: 1×1=1, 1×0=0, 0×1=0, 0×0=0.
- Carrying in binary: Carry over occurs when the product reaches 2 (which is written as 10 in binary).
Example:
- Multiply 101 (binary) by 11 (binary). First, multiply 101 by 1, then multiply 101 by 10, and then add the results.
Likely Questions:
- Multiply 101 (binary) by 10 (binary).
- What is the product of 110 (binary) and 101 (binary)?
- Multiply 111 (binary) by 11 (binary).
- What is 1001 (binary) × 110 (binary)?
- Multiply 1011 (binary) by 10 (binary).
- What is the product of 1100 (binary) and 101 (binary)?
- Multiply 101 (binary) by 101 (binary).
- What is 1101 (binary) × 111 (binary)?
- Multiply 100 (binary) by 111 (binary).
- What is the product of 111 (binary) and 100 (binary)?
5. Use of Symbols
In mathematics, symbols represent numbers or operations. Understanding how to use symbols helps in simplifying mathematical expressions and solving problems.
Key Concepts:
- Mathematical symbols: Symbols like +, -, ×, ÷, =, and others.
- Algebraic symbols: Variables like x, y, and z used to represent unknown values.
Example:
- The symbol “+” means addition, “-” means subtraction, and “=” means equality.
Likely Questions:
- What is the symbol used for addition?
- Which symbol is used for multiplication?
- What does the symbol “=” mean in mathematics?
- Identify the symbol for division.
- What does the symbol “>” indicate?
- What is the symbol for less than?
- What does the symbol “≠” represent?
- Which symbol is used for subtraction?
- What is the symbol for a square root?
- Identify the symbol for exponentiation.
6. Simplification of Algebraic Expressions
Simplifying algebraic expressions means reducing them to their simplest form by combining like terms and performing operations.
Key Concepts:
- Combining like terms: Terms with the same variable and exponent.
- Distributive property: Distribute multiplication over addition or subtraction.
Example:
- Simplify 3x + 4x. Combine the like terms to get 7x.
Likely Questions:
- Simplify 5x + 3x.
- Simplify 7a – 3a + 2a.
- What is the simplified form of 4x + 6x – 2x?
- Simplify 9y + 4y – 3y.
- Simplify 2(3x + 5).
- What is the simplified form of 5(x + 2) – 3(x + 2)?
- Simplify 3a + 2b + a – 4b.
- Simplify 6x + 2x – 4x.
- What is the simplified form of 4(x + y)?
- Simplify 8m + 2n – 5m + 3n.
7. Simple Equations
A simple equation is an equation that has only one unknown. To solve the equation, you isolate the unknown on one side.
Key Concepts:
- Solving for x: Use inverse operations to get the unknown by itself.
- Balance method: What you do to one side, you must do to the other.
Example:
- Solve 2x + 3 = 7. Subtract 3 from both sides to get 2x = 4. Then, divide by 2 to get x = 2.
Likely Questions:
- Solve for x: 2x + 5 = 9.
- Solve for y: 3y – 4 = 8.
- What is the solution to x + 7 = 12?
- Solve for z: 5z = 25.
- Solve for a: 4a – 8 = 16.
- Solve for b: b + 3 = 10.
- What is the solution to 2x + 6 = 10?
- Solve for p: 3p – 2 = 7.
- Solve for m: m/5 = 3.
- What is the solution to 6x + 2 = 14?