In English we use the term "dozens and dozens" to indicate a rather large amount. Dozzina (dozen) certainly exists in Italian, but more often than not, Italian sticks to the metric system. Dieci is precisely ten. Una decina is around ten. Venti is twenty precisely, but poche decine is a few times "about ten" (poche is the plural for poco, therefore meaning "a few," as in a few dozen), so it could mean a quantity anywhere between about eighteen to thirty or even more
Molte famiglie hanno degli ulivi di loro proprietà. Una decina, poche decine, fino a degli uliveti grandi.
Many families have olive trees of their own. Ten odd, twenty odd, up to large olive groves.
Captions 2-3, L'olio extravergine di oliva - Il frantoioPlay Caption
Marika explains about approximate numbers in Italian:
Se io dico che per strada ho visto una cinquantina di alberi, non vuol dire che io ho visto cinquanta alberi, quindi esattamente cinquanta, ma che ho visto all'incirca cinquanta.
If I say that on the road I saw fifty-odd trees, it doesn't mean that I saw fifty trees, and therefore exactly fifty, but that I saw around fifty.
Captions 35-37, Marika spiega - Numeri moltiplicativi, distributiviPlay Caption
There's a unit of weight that's no longer officially used, but which is actually extremely common in Italy, especially when referring to agricultural products. Un quintale (a quintal) is simply the equivalent of one hundred kilos. Alessio talks about the weight of olives compared to the weight of the resulting oil.
Un quintale sono cento chili e la resa...
A quintal is one hundred kilos, and the yield...
Caption 44, L'olio extravergine di oliva - Il frantoioPlay Caption
Although un quintale is considerably less than a ton, it's commonly used to indicate something very heavy, just as when we say, "This thing weighs a ton!" Questo pesa un quintale!
When you don't have un metro (a tape measure, a yardstick) handy, you use alternative measuring devices. Italians often use their arms and legs to give approximate measurements. A man's stride will be around a meter. Le dita (fingers) are used to indicate how much water to put in a pot, how much wine to pour in a glass, or the thickness of a piece of meat or something similar, as in the following example.
Comunque, alta due belle dita, e fatta cucinare nel burro.
In any case, two fingers (an inch) thick, and cooked in butter.
Captions 13-14, L'arte della cucina - L'Epoca delle Piccole RivoluzioniPlay Caption
There are lots of ways to talk about weights and measures. As you progress with Italian, you'll undoubtedly incorporate some of these odd ways of measuring into your everyday conversation.