What is happening
You arrive at a kitchen doubling a recipe for a family gathering.
The doubled batch has to come to thirty-six rotis and the original recipe card has been mislaid.
DoublingRunning
Doubled batch
74rotis
Required batch
36rotis
Doubled batch is over by 38 rotis
Fraction wheel. Original recipe at 37 rotis. Doubled batch 74 rotis, Required batch 36 rotis. Currently doubled batch is over by 38 rotis.
What has to balance