Hint- We must know in such types of questions we should start from the unit and tens place and we must be aware that predecessor means previous number or the number before the given number.
Complete step-by-step answer:
In this question the given number is –
As I mentioned earlier, start from the unit place, so we head to it. We can see that in the unit and tens place there is number 21 and we know in counting before 21 we have 20 or simply head to the unit place we know that before 1 we have 0. Clearly the predecessor of 1 is 0; predecessor of 2 is 1; predecessor of 3 is 2 and so on.
In either way we will get the answer as –
Note – This is a very simple question where we use the concept of higher and smaller numbers but first one must know the word predecessor means ‘previous’ or ‘before‘. To easily do this question first go to the units and tens place of the number or the units and tens place in the question we have number 7654321 if we go to unit place we know that before ‘1’ we have ‘0’ and if we go to the unit as well as tens we have 21 and we know before ‘21‘ we have ‘20’. By using any of these stated methods you will easily find the answer which is 7654320 .