The top row is the recipe for one potion. Below it there is an empty box for every ingredient.
But the witch brews the potion twice. So you need twice as much of every ingredient.
Take one ingredient at a time and add it to itself: 3 moons and another 3 moons make 6 moons.
Write the new amount in the box below that ingredient. The picture next to the box tells you which ingredient it is.
Example
For parents
What does this exercise practice?
The task practices doubling while keeping every amount with its own ingredient. The child combines like with like and learns to read a table column by column along the way.
Common pitfalls
Some children add all the ingredients into one single number. That makes no sense here - spiders and moons stay apart. Point at one picture and ask only about that one ingredient.
How to practice at home
Set the table for twice as many guests: 2 plates, 2 forks, 3 glasses - and now for twice as many people. Each kind of thing is counted on its own.