To find your home’s number, you need to add the digits of your address together to create a single digit. For example, if your address is 724 Main Street, you would add 7+2+4 to get 13, and then add 1+3 to get a final number of 4. Remember to ignore the street name if you live on a numbered street, and use your unit number for the calculation if you live in an apartment. (Source: Second source)