NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 1: Number System - Multiple Choice Questions
Question 15

Question.  15

The product of the successor and predecessor of 999 is

(A)

999000

(B)

998000

(C)

989000

(D)

1998

Detailed Answer with Explanation:

Step 1: Find the successor of 999.

Successor means the next number: \(999 + 1 = 1000\).

Step 2: Find the predecessor of 999.

Predecessor means the previous number: \(999 - 1 = 998\).

Step 3: Multiply the two numbers.

We need \(1000 \times 998\).

Easy place-value method:

\(998 \times 1000\) just adds three zeros: \(998000\).

Or, using distributive property:

\(1000 \times 998 = 1000 \times (1000 - 2)\)

\(= 1000 \times 1000 - 1000 \times 2\)

\(= 1000000 - 2000\)

\(= 998000\).

Answer: \(998000\) → Option B.

NCERT Exemplar Solutions Class 6 – Mathematics – Unit 1: Number System – Multiple Choice Questions | Detailed Answers