In general, you do not need to learn specific rule numbers and case names. However, in certain areas, you will impress the graders if you do so. One of these is when being tested on the UCC. Try to memorize the following rule numbers and understand the concept behind them:
UCC 2-201 - Statute of Frauds and Exceptions - (1) Contract for the sale of goods for the price of $500 or more must be in writing (2) But between merchants, if within a reasonable time a writing in confirmation (confirmatory memorandum) of the contract is received and the party receiving it has reason to know its contents, it satisfies the requirements of the Statute of Frauds against such party unless written notice of objection to its contents is given within 10 days after it is received (3) Or if the goods are to be specially manufactured for the buyer and are not suitable for sale to others in the ordinary course of the seller's business and the seller, before notice of repudiation is received and under circumstances which reasonably indicate that the goods are for the buyer, has made either a substantial beginning of their manufacture or commitments for their procurement. (Note that the Statute of Frauds also includes other types of contracts, but for purposes of the UCC, this is the relevant one)
UCC 2-205 - Firm Offers - As a general rule, all offers are revocable at any time prior to acceptance, even those offers that purport to be irrevocable on their face. An exception to this general rule exists under the Merchants Firm Offer Rule. Under UCC 2-205, an offer by a merchant to buy or sell goods in a signed record that by its terms gives assurance that it will be held open is not revocable for lack of consideration, during the time stated or if no time is stated for a reasonable time, not exceeding three months. (Remember that just because a merchant CAN withdraw their offer after three months, it doesn't mean they MUST, and if they DON'T, their firm offer is still enforceable.)
UCC 2-207 Battle of the Forms - Unlike in common law, an acceptance under the UCC does not have to mirror the offer. Under UCC 2-207, (1) A definite and seasonable expression of acceptance or a written confirmation which is sent within a reasonable time operates as an acceptance even though it states terms additional to or different from those offered or agreed upon, unless acceptance is expressly made conditional on assent to the additional or different terms. (2) The additional terms are to be construed as proposals for addition to the contract. Between merchants such terms become part of the contract unless:(a) the offer expressly limits acceptance to the terms of the offer;(b) they materially alter it; or(c) notification of objection to them has already been given or is given within a reasonable time after notice of them is received. And (3) Conduct by both parties which recognizes the existence of a contract is sufficient to establish a contract for sale although the writings of the parties do not otherwise establish a contract. In such case the terms of the particular contract consist of those terms on which the writings of the parties agree, together with any supplementary terms incorporated under any other provisions of the UCC.
UCC 2-209 - Modification, Rescission, and Waiver - An agreement modifying a contract within this Article needs no consideration to be binding, but must meet the statute of frauds if the contract is governed by the statute of frauds.... A party who has made a waiver affecting an executory portion of the contract may retract the waiver by reasonable notification received by the other party that strict performance will be required of any term waived, unless the retraction would be unjust in view of a material change of position in reliance on the waiver.
UCC 2-201 - Statute of Frauds and Exceptions - (1) Contract for the sale of goods for the price of $500 or more must be in writing (2) But between merchants, if within a reasonable time a writing in confirmation (confirmatory memorandum) of the contract is received and the party receiving it has reason to know its contents, it satisfies the requirements of the Statute of Frauds against such party unless written notice of objection to its contents is given within 10 days after it is received (3) Or if the goods are to be specially manufactured for the buyer and are not suitable for sale to others in the ordinary course of the seller's business and the seller, before notice of repudiation is received and under circumstances which reasonably indicate that the goods are for the buyer, has made either a substantial beginning of their manufacture or commitments for their procurement. (Note that the Statute of Frauds also includes other types of contracts, but for purposes of the UCC, this is the relevant one)
UCC 2-205 - Firm Offers - As a general rule, all offers are revocable at any time prior to acceptance, even those offers that purport to be irrevocable on their face. An exception to this general rule exists under the Merchants Firm Offer Rule. Under UCC 2-205, an offer by a merchant to buy or sell goods in a signed record that by its terms gives assurance that it will be held open is not revocable for lack of consideration, during the time stated or if no time is stated for a reasonable time, not exceeding three months. (Remember that just because a merchant CAN withdraw their offer after three months, it doesn't mean they MUST, and if they DON'T, their firm offer is still enforceable.)
UCC 2-207 Battle of the Forms - Unlike in common law, an acceptance under the UCC does not have to mirror the offer. Under UCC 2-207, (1) A definite and seasonable expression of acceptance or a written confirmation which is sent within a reasonable time operates as an acceptance even though it states terms additional to or different from those offered or agreed upon, unless acceptance is expressly made conditional on assent to the additional or different terms. (2) The additional terms are to be construed as proposals for addition to the contract. Between merchants such terms become part of the contract unless:(a) the offer expressly limits acceptance to the terms of the offer;(b) they materially alter it; or(c) notification of objection to them has already been given or is given within a reasonable time after notice of them is received. And (3) Conduct by both parties which recognizes the existence of a contract is sufficient to establish a contract for sale although the writings of the parties do not otherwise establish a contract. In such case the terms of the particular contract consist of those terms on which the writings of the parties agree, together with any supplementary terms incorporated under any other provisions of the UCC.
UCC 2-209 - Modification, Rescission, and Waiver - An agreement modifying a contract within this Article needs no consideration to be binding, but must meet the statute of frauds if the contract is governed by the statute of frauds.... A party who has made a waiver affecting an executory portion of the contract may retract the waiver by reasonable notification received by the other party that strict performance will be required of any term waived, unless the retraction would be unjust in view of a material change of position in reliance on the waiver.