Santa's Register

An
elf discovered Santa Claus's gift register.
While flipping through it, he noticed that pages were missing, and the
register jumped from page 24 to page 45.
Question:
How many sheets are missing from Santa Claus's register?
Answer:
10
sheets have disappeared.
44 -
24 = 20
One
sheet = 2 pages.
So, 20
/ 2 = 10