When it comes to buying the big stuff -- a jumbo jet, an island, or 6 million bushels of wheat -- our government can handle it. Uncle Sam knows how to deal with big bucks. But send a civil servant out to buy a pencil, take a cab, or make some other small, out-of-pocket expenditure and it becomes a federal case.

Finding streamlined methods to handle little office chores in our government is often easier said than done. Consider this memo from an Agriculture Department unit, aimed at advising the staff how to handle petty cash situations:

"SUBJECT: Refinement of Emergency Small Puchase Procedures. The following information is provided to further refine procedures for emergency purchases discussed in earlier memos of Oct. 11, 1979 and Feb. 27, 1980.

"1. Obtain telephone approval of all such purchases from Elton Polen, Dorothy Whitehead, or Margaret Bates, FAS Management Services, X75145, who will maintain a log of your calls.

"2.Obtain a sales tax exemption form from any of the following locations and take it with you when making the purchase.

"Budget & Fiscal -- Room 1248-S (Charlotte Simasek).

"Technical Assistance -- Room 101 PP (Cathy Watkins).

"International Research -- Room 459 (Shirley Potter).

"Scientific and Technical Exchanges -- Room 3104A Auditors (Virginia Williams).

"3. Please use your own money to make the initial purchase unless the PURCHASE UNLESS THE PURCHASE IS MORE THAN $20. Otherwise, follow the procedure outlined in paragraph 8.

"4. When your purchase is completed, (a) request that the vendor sign the sales tax exemption form and (b) obtain a receipt.

"5. Prepare an SF 1164 (taxi voucher form), attach the sales tax form and receipt, and have the SF 1164 approved by your deputy director or assistant director. Take to OICD Budget & Fiscal Office, Room 1248-S for obligation. Go to FAS Management Services, Room 0664-S, for approval, and then to the imprest fund cashier, Room 6082-S, for reimbursement.

"6. When ordering by mail, please follow the same procedures outlined in paragraph 1, using a personal check for your purchase. We do not want to request FAS to issue purchase orders for small amounts as it takes too much time and delays other work. You do not need to use sales tax exemption forms for mail order purchases outside of D.C.

"7. Anyone on travel status is not expected to follow the same procedure. Simply obtain receipts for purchases and attach to your travel voucher for reimbursement. Explain on the voucher why the purchase was necessary.

"8. To obtain a cash advance for these purchases:

"a) Get authorizatin memo from Budget and Fiscal.

"b) Take FAS imprest -- Fill out a two-part SF 1165 (interim receipt for cash) get cash and one copy of SF 1165.

"c) When making purchase, have vendor sign your copy of SF 1165 and obtain reciept.

"d) To clear the cash advance, complete an SF 1164, following the procedures outlined in paragraph 6, and attach your copy of the SF 1165, signed by the vendor. Employes are responsible for the entire amount of the advance and must turn in receipts and any cash advance balance equaling the total amount of the advance to the FAS imprest cashier."