Answer:
To determine how many cups Jayla needs to measure 420 milliliters of milk, we need to convert milliliters to cups.
1 cup is equivalent to 236.588 milliliters.
To find the number of cups needed, we can divide 420 milliliters by the conversion factor of 236.588 milliliters per cup:
420 milliliters ÷ 236.588 milliliters/cup = 1.776 cups.
Therefore, Jayla would need approximately 1.776 cups of milk for the custard recipe.