What is the best method to figure out this sort of question please?

In the following calculation, two digits have been accidentally switched. Find the two digits that need to be switched back to make the calculation correct.

5070 divided by 87 = 65


Answer = 8 & 7

AND

1234 x 5678 = 7024412

Answer = 4 & 8

Sorry newbie, I know this doesn't help.... I haven't a clue! Those are dreadful questions to expect a 10/11year old to work out!!

Perhaps the answer is skip it and move on as it will take too long to answer?

Are they testing time management and knowing when to take a guess.

I know of no method that you could do in under a minute to solve it. Actually, thinking about the top 1, you know the 5 or 7 is in the wrong place as 7x5 =35, buthow you decide which numbers need to be swapped without trial and error I don’t know

Where are the questions from?

If something set by a tutor, one hopes that your fees include a detailed explanation of how a year 6 child should tackle them within the time constraints of an 11+ selection test.

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Outside of a dog, a book is a man's best friend. Inside of a dog it's too dark to read.Groucho Marx

Which area are you? For example the information for the Birmingham consortium of schools states the level of maths required is ‘up to and including’ the year 5 curriculum.
Personally I don’t see the point in tackling maths like this- it’s likely to confuse the child. When DC went through a couple Bond books as practice my stance was that if my DC had not come across that level of maths at school, then I told them to ignore them and to not to even try them. DC found the books had many questions that were beyond the year 5 curriculum, so they were put aside!