Devin decided to make a cake to surprise his mother the rest in peace said he needed 4 deciliters of milk how many liter of milk did he need

we are given that

4 deciliters of milk

we know that

1 deciliter = 0.1 liter

we have find for 4 deciliter

so, we can multiply both sides by 4

and we get

4*1 deciliter = 4*0.1 liter

4 deciliter = 0.4 liter

so, he needed 0.4 liter of milk ... Answer