An acrostic uses the first letters of words in a sentence and forms a "hidden" word from them like this:
"Read everywhere, all day!" spells "read."
For younger children
You can send your child secret messages using acrostics. Teach your child how acrostics work. Then write her a note, using colourful markers and fold it up and seal it in an envelope. Include a pen and blanks for the child to fill in as she decodes the message. Don't worry if your clue doesn't form a proper sentence - the goofier the better.
For older kids
Acrostics can be very tricky to create. Older kids can create poetry or prose, with acrostics hidden in them. Get them to challenge themselves by taking a crack at creating one.
Acrostics in Alice in Wonderland
Oh, that Lewis Carroll! He wove acrostics into Through the Looking Glass.
The last five lines in the final chapter spell out "Alice."
A boat, beneath a sunny sky
Lingering onward dreamily
In an evening of July—
Children three that nestle near,
Eager eye and willing ear.
So, yeah, writing a masterpiece wasn't enough - he had to include an acrostic? Show-off. (OK, that's jealousy talking. That dude was one talented rabbit.)