Class 8 Maths Online Practice Test – Squares & Cubes
Welcome to the **Class 8 Maths Online Practice Test**. This free online examination is designed to help students strengthen their understanding of **Squares, Square Roots, Cubes and Cube Roots**.
The test contains **20 multiple-choice questions for 20 marks**, with **1 mark for each question**. Students can attempt the questions online, use the question navigation panel, check their answers, and view their **score, percentage, correct answers and explanations** after completing the test.
⏱️ **Time:** 20 Minutes
📝 **Questions:** 20
🎯 **Total Marks:** 20
📚 **Topic:** Squares, Square Roots, Cubes & Cube Roots
This practice test is useful for **Class 8 students, school examinations and regular mathematics practice**. Try to complete the test within the given time and review the explanations carefully after submission.
**All the Best! 🎯 Keep Practising, Keep Improving!**
STD 8 MATHS
Online Practice Examination
Class 8 Mathematics Examination
Instructions:
Choose the correct answer from the given options.
Questions
Marks
Minutes
Each question carries 1 mark.
🎉 Examination Completed
0/20
Score
Correct
Wrong
Unanswered
Percentage:
0%
/* ===================================================== QUESTION DATABASE ===================================================== */
const questions = [
{ q:`A perfect square number having m digits, where m is even will have square root with`, options:[ `m/2 digits`, `m digits`, `m + 1 digits`, `m − 1 digits` ], answer:0, explanation:`A perfect square having an even number of digits has a square root with half as many digits. Therefore, the answer is m/2 digits.` },
{ q:`The cube root of 6859 is`, options:[ `19`, `18`, `17`, `21` ], answer:0, explanation:`19 × 19 × 19 = 6859. Therefore, ∛6859 = 19.` },
{ q:`The ones digit of the cube of 23 is`, options:[ `3`, `6`, `7`, `9` ], answer:2, explanation:`23³ = 12167. Therefore, the ones digit is 7.` },
{ q:`The value of 1 + 3 + 5 + 7 + 9 + 11 + 13 is`, options:[ `36`, `41`, `49`, `52` ], answer:2, explanation:`The sum of the first 7 odd numbers is 7² = 49.` },
{ q:`Which of the following is the cube of an even natural number?`, options:[ `1331`, `4913`, `3375`, `1728` ], answer:3, explanation:`1728 = 12³ and 12 is an even natural number.` },
{ q:`The value of 23³ − 22³ is`, options:[ `1518`, `1519`, `1421`, `1420` ], answer:1, explanation:`23³ = 12167 and 22³ = 10648. Therefore, 12167 − 10648 = 1519.` },
{ q:`A number ending in 9 will have the unit place of its square as`, options:[ `1`, `3`, `9`, `6` ], answer:0, explanation:`A number ending in 9 has a square ending in 1. For example, 19² = 361.` },
{ q:`How many numbers lie between the squares of 13 and 14?`, options:[ `28`, `26`, `13`, `14` ], answer:1, explanation:`14² − 13² − 1 = 196 − 169 − 1 = 26.` },
{ q:`Which of the following numbers is not a perfect cube?`, options:[ `216`, `343`, `125`, `667` ], answer:3, explanation:`216 = 6³, 343 = 7³ and 125 = 5³. 667 is not a perfect cube.` },
{ q:`What is the value of (∛64 + ∛125) / ∛27?`, options:[ `2`, `3`, `4`, `9` ], answer:1, explanation:`∛64 = 4, ∛125 = 5 and ∛27 = 3. Therefore, (4 + 5)/3 = 3.` },
{ q:`The smallest square number that is divisible by each of the numbers 2, 3 and 8 is`, options:[ `64`, `144`, `1296`, `576` ], answer:1, explanation:`The LCM of 2, 3 and 8 is 24. The smallest perfect square divisible by 24 is 144.` },
{ q:`The partner factors of 25 is/are`, options:[ `1, 25`, `5, 5`, `2, 25`, `Both (a) and (b)` ], answer:3, explanation:`25 has factor pairs (1,25) and (5,5). Therefore, both (a) and (b) are correct.` },
{ q:`Which of the following is not a unit digit of a square number?`, options:[ `0`, `4`, `6`, `8` ], answer:3, explanation:`A perfect square can have unit digits 0, 1, 4, 5, 6 or 9. It cannot end in 8.` },
{ q:`The cube of 24 is`, options:[ `12167`, `15625`, `13824`, `10648` ], answer:2, explanation:`24³ = 24 × 24 × 24 = 13824.` },
{ q:`The value of 198² − 197² is`, options:[ `393`, `395`, `295`, `293` ], answer:1, explanation:`Using a² − b² = (a+b)(a−b): (198+197)(198−197) = 395 × 1 = 395.` },
{ q:`The square root of 196 is`, options:[ `12`, `11`, `15`, `14` ], answer:3, explanation:`14 × 14 = 196. Therefore, √196 = 14.` },
{ q:`Which of the following number is a perfect cube?`, options:[ `243`, `512`, `392`, `8640` ], answer:1, explanation:`512 = 8³. Therefore, 512 is a perfect cube.` },
{ q:`Which of the following is a square of an even number?`, options:[ `144`, `169`, `441`, `625` ], answer:0, explanation:`144 = 12² and 12 is even.` },
{ q:`If 45² = 2025 then 46² is equal to`, options:[ `2025 + 46`, `2025 + 46²`, `2025 + 23²`, `2025 + 91` ], answer:3, explanation:`46² − 45² = (46−45)(46+45) = 1 × 91 = 91. Therefore, 46² = 2025 + 91.` },
{ q:`The value of 21 + 23 + 25 + 27 + 29 is equal to`, options:[ `33`, `63`, `43`, `125` ], answer:3, explanation:`21 + 23 + 25 + 27 + 29 = 125. Note: The supplied answer key stated 53, but the correct mathematical answer is 125.` }
];
/* ===================================================== VARIABLES ===================================================== */
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let timeLeft = 20 * 60;
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/* ===================================================== SELECT ANSWER ===================================================== */
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/* ===================================================== NEXT QUESTION ===================================================== */
function nextQuestion(){
if(currentQuestion < questions.length - 1){ currentQuestion++; loadQuestion(); }else{ if( confirm( "You have reached the last question. Submit the exam?" ) ){ finishExam(); } } } /* ===================================================== PREVIOUS ===================================================== */ function previousQuestion(){ if(currentQuestion > 0){
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loadQuestion();
}
}
/* ===================================================== MARK FOR REVIEW ===================================================== */
function toggleMark(){
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/* ===================================================== PROGRESS ===================================================== */
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/* ===================================================== TIMER ===================================================== */
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/* ===================================================== ANSWER REVIEW ===================================================== */
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📋 Answer Review
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questions.forEach((q,index)=>{
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Your Answer: ${yourAnswer}
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Explanation: ${q.explanation} `;
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