John Thomas Gaudlock was tried by a Hall County jury and convicted of unlawfully possessing both cocaine 1 and more than an ounce of marijuana. 2 He appeals from the judgment of conviction, asserting that the State failed to adduce sufficient evidence at trial of his possession of more than an ounce of marijuana and that the trial court erred when it admitted evidence of a similar transaction. We see no error and affirm.

*150 1. We first consider whether the evidence adduced at trial is sufficient to sustain the conviction for possession of more than an ounce of marijuana. 3 Gaudlock does not dispute that the State presented competent evidence that he possessed marijuana and that the marijuana in his possession had a weight of 28.8 grams, and he also does not dispute that 28.8 grams is more than an ounce. He claims, however, that the evidence is insufficient to sustain his conviction because no witness testified about how many grams equal an ounce. We find no merit in this claim.

The possession of an ounce or less of marijuana is a misdemeanor, see OCGA § 16-13-2 (b), and the possession of more than an ounce of marijuana is a felony. See OCGA § 16-13-30 (j). So, to prove felony possession of marijuana, the State must prove that the weight of the marijuana exceeded one ounce. See Whatley v. State, 189 Ga. App. 173, 175 (4) (375 SE2d 245) (1988). But to discharge this burden, we do not think that it is necessary for the State to come forward with evidence of how many grams equal an ounce, even if its witnesses testify about the weight of the marijuana in terms of grams. 4 This is because the word “ounce” — as that word is used in the relevant statute, OCGA § 16-13-2 (b) — has a definite and precise meaning, and its meaning is a question of law, not fact. 5 See Expedia, Inc. v. City of Columbus, 285 Ga. 684, 689 (4) (681 SE2d 122) (2009) (“The interpretation of statutes and ordinances is a question of law. . . .”) (citation omitted). When the statute refers to an “ounce” of marijuana, it refers, as a matter of law, to an avoirdupois ounce, which is the equivalent of, when rounded up to the nearest hundredth of a gram, 28.35 grams. 6 See Pasuer v. State, 271 Ga. App. 259, *151 260, n. 3 (609 SE2d 193) (2005), overruled on other grounds, Vergara v. State, 283 Ga. 175, 177 (1) (657 SE2d 863) (2008). The number of grams in an ounce is not something that varies from case to case or is open to reasonable dispute. Because the State adduced evidence at trial that Gaudlock had possession of 28.8 grams of marijuana — which is, by definition, more than one ounce of marijuana — the evidence is sufficient to sustain the conviction for possession of more than one ounce of marijuana.

2. We next consider whether the trial court abused its discretion when it admitted evidence of a similar transaction. 7 The evidence in this case shows that, on April 27, 2008, a Gainesville police officer stopped a vehicle in which Gaudlock was a passenger. After the driver and another passenger exited this vehicle — leaving Gaudlock as its only remaining occupant — the officers saw several bags thrown from the vehicle. Officers searched the area around the vehicle and found two bags containing marijuana and a third bag containing 1.87 grams of cocaine. The convictions in this case are based on Gaudlock’s possession of this marijuana and cocaine.

The prosecuting attorney asked the trial court to permit the State to present evidence at trial that Gaudlock also had been found in possession of cocaine on April 15, 2008, less than two weeks before the incident that gave rise to the charges for which Gaudlock was being tried. After a hearing, at which the trial court determined that the evidence of the April 15 incident was probative of whether Gaudlock had an intent to possess the cocaine thrown from the vehicle on April 27, the trial court gave the State leave to present such evidence at trial. The State did so, and this evidence shows that, on April 15, a confidential informant working with the Gainesville Police Department met Gaudlock and asked if he knew where the informant could buy cocaine. Gaudlock said that he did, and he directed the informant to a nearby location. At that location, Gaudlock retrieved less than a gram of cocaine and then sold it to the informant.

As our Supreme Court has explained, before evidence of another *152 crime may be admitted as a similar transaction,

the State must show that it seeks to introduce the evidence for an appropriate purpose; that there is sufficient evidence to establish that the accused committed the independent act; and that there is a sufficient connection or similarity between the independent act and the crime charged so that proof of the former tends to prove the latter.

Johnson v. State, 289 Ga. 22, 24 (2) (709 SE2d 217) (2011) (citation and punctuation omitted). Gaudlock does not dispute that the State offered evidence of the April 15 incident for an appropriate purpose, to show intent, or that there is sufficient evidence to establish that Gaudlock possessed cocaine on April 15. Instead, Gaudlock contends that the April 15 incident is not similar enough to the April 27 incident because he sold cocaine on April 15, whereas he was charged only with simple possession of cocaine on April 27. We do not agree.

“When considering the admissibility of similar transaction evidence, the proper focus is on the similarities, not the differences, between the separate crimes and the crimes in question.” Hall v. State, 287 Ga. 755, 757 (2) (699 SE2d 321) (2010). Here, both incidents involved the possession of cocaine. The possession on April 15 was for the purpose of distribution — inasmuch as the evidence shows that Gaudlock did, in fact, distribute the cocaine on that occasion — and the possession on April 27 was for an unknown purpose and not clearly for personal use. 8 One incident involved possession and sale of less than one gram of cocaine, the other involved possession of less than two grams of cocaine. Both incidents occurred in Hall County within a span of two weeks. Given these similarities, we cannot conclude that the trial court abused its discretion in this case. See Slaughter v. State, 282 Ga. App. 276, 279 (1) (638 SE2d 417) (2006) (trial court did not err in cocaine trafficking case when it admitted evidence that defendant had, on another occasion, possessed one “rock” of crack cocaine); Drummond v. State, 278 Ga. App. 631, 633 (1) (629 SE2d 543) (2006) (trial court did not err in cocaine trafficking case when it admitted *153 evidence of similar transaction involving possession of one “hit” of cocaine).

For these reasons, we affirm the judgment of conviction below.

Judgment affirmed.