SOACHA, Colombia — Already, two of Gloria Vásquez’s children had dropped out of school during the pandemic, including her 8-year-old, Ximena, who had fallen so far behind that she struggled with the most basic arithmetic.

“One plus one?” Ms. Vásquez quizzed her daughter one afternoon.

“Four?” the little girl guessed helplessly.

Now, Ms. Vásquez, a 33-year-old single mother and motel housekeeper who had never made it past the fifth grade, told herself she couldn’t let a third child leave school.

“Where’s Maicol?” she asked her children, calling home one night during another long shift scrubbing floors. “Is he studying?”

have returned to the classroom, 100 million children in Latin America are still in full or partial distance learning — or, as in Maicol’s case, some distant approximation of it.

The consequences are alarming, officials and education experts say: With economies in the region pummeled by the pandemic and connections to the classroom so badly frayed, children in primary and secondary school are dropping out in large numbers, sometimes to work wherever they can.

1.8 million children and young people abandoned their educations this school year because of the pandemic or economic hardship, according to the national statistics agency.

Ecuador lost an estimated 90,000 primary and secondary school students. Peru says it lost 170,000. And officials worry that the real losses are far higher because countless children, like Maicol, are technically still enrolled but struggling to hang on. More than five million children in Brazil have had no access to education during the pandemic, a level not seen in more than 20 years, Unicef says.

Increased access to education was one of the great accomplishments of the last half century in Latin America, with enrollment soaring for girls, poor students and members of ethnic and racial minorities, lifting many toward the middle class. Now, an onslaught of dropouts threatens to peel back years of hard-won progress, sharpening inequality and possibly shaping the region for decades to come.

some of the world’s worst outbreaks, yet several South American nations are now experiencing their highest daily death tolls of the crisis, even after more than a year of relentless loss. For some governments, there is little end in sight.

But unless lockdowns end and students get back into the classroom soon, “many children may never return,” the World Bank warns. And “those who do go back to school will have lost months or even years of education.” Some analysts fear the region could be facing a generation of lost children, not unlike places that suffer years of war.

Even before the pandemic, graduating from high school in Ms. Vásquez’s neighborhood was no small feat.

She and her children live at the end of a dirt road, just beyond Bogotá, Colombia’s sprawling, mountain-flanked capital, a deeply unequal city in one of the most unequal regions in the world. Violence and crime are as common here as the ice cream cart that circles the block each afternoon. For some children, the pandemic has been yet another trauma in a seemingly endless succession.