Thank you all for the very useful responses. I got a bit confused about the awesome fact, that the mods actually check my post first & thats why it took me so long to receive your solutions.
Keep on expanding your Factories.

Big hello too all the Engineers I have two chestws with iron. Chest one contains 100 iron. Chest two contains 50 iron. I woud like to compare the amount of iron in the two chests with a decider combinator. Unfortuantely the decider combinator adds up the two values to a total of 150 iron regardless ...