How can you make number one disappear by adding something to it?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

When we see 2 but call 10?

Why is Saturday stronger than Monday?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

Can you quickly find which two matchstick figures are identical?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?