Apostrophes have two diferent purposes. They connect two words together: “It is” turns into “It’s”. They can also be for someones property. It sometimes comes before the s.
In maths we have been working on decimals. Decimals are things that can represent wholes or percentiges. When you go to the shops you get something £2.50 the 2 that represents units.
The 5 represnts 5 tenths and the 0 represnts hundredths.