First add up how many sacks the known months already need.
Subtract that from the store. That is what is left for the empty months.
Share the rest out equally among the empty months.
Example
For parents
What does this exercise practice?
Winter rations combine two steps: first work out a balance, then share the rest fairly.
Common pitfalls
The rest is often written into just one month. But all empty months get the same amount.
How to practice at home
Share a pack of biscuits over the remaining days of the week so every day gets the same.