Four activists from the National Organization for Women (NOW) yesterday visited a class and leafletted outside the Science Center, urging students to take a semester off to work to ratify the Equal Rights Amendment (ERA).

The "action team" of four ERA members, three of whom are students taking a year off, is launching a "countdown campaign" on 25 northeastern college campuses to recruit students to organize on campuses and to travel to states that have not ratified the amendment.

The amendment needs to be ratified by three more states by June 30, 1982 to become part of the constitution. If it is not passed by then, "you all won't see it ratified in your lifetime," Irene McCabe told a predominantly female group of about 150 students in Biology 109, "Biology and Women's Issues," yesterday afternoon.

NOW's goal is "not to convert the negative people but just activate the people who support us already." McCabe, who is taking a year off from her job as a psychologist, added, noting that polls show that 63 per cent of the national population and almost 70 per cent of all students support ERA.

"It's sort of a Paul Revere effect--not to proselytize, just to alert," she said.

The team is concentrating on Northeastern colleges because of the schools' reputation for activism, Jennifer Jackman, an organizer on leave from Smith College, said yesterday.

"We're hoping students will respond to this emergency as they have to others the country has been in, and consider the ERA a continuation of the civil rights movement," she added.

Signs Bright

Response to NOW's efforts so far has been "amazing," Deborah B. DeBare, an organizer from Brown, said yesterday. When NOW held a conference in Washington last weekend, it raised $35,000 in less than an hour, DeBare said, adding, "People went crazy writing checks."

The increasing tendency of women to vote differently from men as a group--starting with the 1980 presidential election, when 16 per cent fewer women than men voted for President Reagan--also improves ERA's chances of passing, she said

Besides recruiting students to take time off, the team will hold a symposium Sunday evening in Dunster House and a rally Monday at Boston University before leaving for Northampton, Providence and other campus areas.

The "countdown campaign" on Northeastern campuses coincides with similar efforts on the West Coast and in the South and with a national media campaign by NOW, Laurie Goldstein, national press coordinator for NOW, said yesterday.