This is quite an intriguing worksheet as it is difficult to decide if there is a best possible answer. In fact, part of the challenge could be to decide what the criteria are for deciding what counts as the best possible answer.
The idea is to use each of the digits 0 to 9 just once each to fulfil the statements below. So, for example 98 could be used for the largest even number and 67 used as the largest odd number. But is this the best option? Would 86 and 97 be better?
One which does have to be considered early on is the multiple of five as this ensures either the digit 5 or the digit 0 are used.
A good worksheet to generate discussion and with no answer it is entirely up to you!
This page can be found in the Year 5 Using and Applying Maths category.