NCERT Solutions Class 7 Maths Chapter 3 — Decimals

Solution:

Step 1: In the number 7.348, the digit '7' is in the units place.

Step 2: The digit '3' is in the tenths place, meaning 3/10.

Step 3: The digit '4' is in the hundredths place, meaning 4/100.

Step 4: The digit '8' is in the thousandths place, meaning 8/1000.

Solution:

Step 1: To convert 3/8 to a decimal, we perform the division 3 ÷ 8.

Step 2: 3 ÷ 8 = 0.375.

Step 3: Rohan incorrectly assumed that the denominator '8' directly relates to the hundredths place '8' when it does not. The correct decimal representation is 0.375, not 0.38.

Solution:

Step 1: To compare 0.6 and 0.55, it's helpful to make them have the same number of decimal places.

Step 2: 0.6 can be written as 0.60 (adding a zero at the end does not change its value).

Step 3: Now, compare 0.60 and 0.55. Looking at the hundredths place, 60 is greater than 55.

Step 4: Therefore, 0.6 is greater than 0.55.

Solution:

Step 1: We know that 1 rupee = 100 paise.

Step 2: Therefore, 75 paise can be written as 75/100 of a rupee.

Step 3: As a decimal, 75/100 is 0.75.

Step 4: Combining the rupees and paise, 7 rupees and 75 paise is 7 + 0.75 = ₹ 7.75.

Solution:

Step 1: When adding decimal numbers, it is essential to align the decimal points vertically.

Step 2: This ensures that digits with the same place value are added together (e.g., tenths with tenths, hundredths with hundredths, ones with ones).

Step 3: If the decimal points are not aligned, you would be adding digits from different place values, leading to an incorrect sum.

Step 4: While having the same number of digits after the decimal (by adding trailing zeros) can be helpful, it's not strictly 'crucial' like aligning the decimal point, which is non-negotiable for correct addition.