It is a Chinese folktale that features a magical pot that doubles everything that is put inside it!
After reading you could play a hands-on game where students roll a dice and put a number of counters into a container and then pull out double!
You need:
- a container - perhaps one that looks like a cauldron or big pot
 - math counters
 - dice - use a number to suit your learners, 6, 12 0r 20 sided dice for example
 
- fill the container with counters so there are plenty inside ready to play
 - put some counters outside the container too
 - show students how to roll a die and take the matching number of counters - e.g. 4
 - place the counters inside the container
 - model for students some strategies to find the double of the number rolled if needed e.g. knowing double 4 is 8 as a fact, counting on from 4, 5, 6, 7, 8, using a number line or making 2 equal towers using connecting cube equipment
 - pull out counters to show the double - e.g. 8
 - model mathematical language - double 4 is 8, 4 and 4 more is 8, 4 add 4 is 8
 - model for students how to record this with pictures of numbers on your class chart paper or board
 - let all students have a turn in whole group or as a partner play game
 
The text is on the lengthier side - perfect for first and second grade. I have read it to kindergarten before, but improvised on the text as I read, making the language and length more manageable for them.
Find more ideas for doubles: