Matching up torn pages on Shabbos

Hi,

If a page in a book is torn, one may align the two parts on Shabbos in reading the book; this is not called writing, and separating the parts is not called erasing.

However, one may not align the two parts if there is a particular letter which is split, and which would not be readable without aligning the parts.

(Rav Moshe Feinstein, Igrot Moshe Yoreh Deah 2:75)

פתקא טבא,
Mordechai

Page number displays on Shabbat

Hi,

One may post individual cards displaying digits in order to show people the proper page number during davening on Shabbat, even though one is thereby "writing" a coherent message in placing the cards side-by-side. This is permitted so long as the cards are not joined to each other.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 1:135)

Have a great day,
Mordechai