Based On Decimal Video Lecture | Quantitative Aptitude for SSC CGL

Ans. A decimal number is a number that is expressed in base 10, using the digits 0-9. It represents a fraction with a denominator of a power of 10. For example, 3.14 is a decimal number, where 3 is the whole number part and 14 is the fractional part.

Ans. To convert a decimal number to a fraction, you can follow these steps: 1. Identify the decimal part as the numerator. 2. Determine the place value of the last digit in the decimal part. 3. Write the decimal part as the numerator and the place value as the denominator. 4. Simplify the fraction, if possible. For example, to convert 0.75 to a fraction: 1. The decimal part is 75. 2. The last digit is in the hundredth place. 3. Writing 75 as the numerator and 100 as the denominator, we get 75/100. 4. Simplifying the fraction, we get 3/4.

Ans. Rounding a decimal number involves approximating it to a certain number of decimal places or significant figures. The general rule for rounding is: - If the digit following the desired decimal place is less than 5, round down (keep the desired decimal place unchanged). - If the digit following the desired decimal place is 5 or greater, round up (increase the desired decimal place by one). For example, rounding 3.14159 to 2 decimal places: - The digit following the second decimal place is 5, so we round up. - The rounded value is 3.14.

Ans. To perform arithmetic operations with decimal numbers, you can follow the same rules as with whole numbers. The key is to align the decimal points before carrying out the operation. Here's a brief explanation for each operation: - Addition and Subtraction: Align the decimal points and add or subtract the digits as you would with whole numbers. Keep the decimal point in the result aligned with the decimal points in the numbers being operated on. - Multiplication: Ignore the decimal points and multiply the numbers as if they were whole numbers. Count the total number of decimal places in both numbers and place the decimal point in the result so that it has the same number of decimal places. - Division: Move the decimal point in the divisor to the right until it becomes a whole number. Move the decimal point in the dividend the same number of places. Perform the division as if the numbers were whole numbers. Place the decimal point in the quotient to match the number of decimal places in the dividend.

Ans. To compare decimal numbers, you can follow these steps: 1. Start by comparing the whole number parts of the decimals. The greater whole number determines the comparison result. 2. If the whole number parts are equal, compare the decimal parts digit by digit from left to right until a difference is found. The decimal number with the greater digit determines the comparison result. 3. If all decimal digits are equal, the decimal numbers are considered equal. For example, to compare 3.75 and 3.7: 1. The whole number parts (3) are equal. 2. The first decimal digit (7 vs. 7) is equal. 3. The second decimal digit (5 vs. 0) is greater in 3.75. Therefore, 3.75 is greater than 3.7.