You will need 2.8 canisters.
To determine this, you need to know the quantity of breadcrumbs required for one meatloaf and how many meatloafs you are planning to make. Since the breadcrumbs are sold by the canister, you will also need to know the quantity of breadcrumbs in one canister. With this information, you can calculate the total quantity of breadcrumbs required for all the meatloafs and divide it by the quantity of breadcrumbs in one canister to find out how many canisters you need to buy.