A Polk County teacher has posted her resignation letter online and it's gone viral.

Wendy Bradshaw said she can't justify making students cry anymore. She said the problem is standardized testing.

"How am I supposed to be an effective teacher when I'm not allowed to do what is best for students?" she said.

In her letter, Bradshaw complains about standardized testing that she said forces students to perform tasks that are too advanced for them, leaving them discouraged.

"You can see their eyes fill up with tears," Bradshaw said.

She gives examples of young children working on outdated computers that they don't know how to use very well or struggling to read tests that are poorly written.

"My biggest concern is that basically our youngest children are being subjected to educational malpractice. It's not an education anymore, it's not teaching them to love learning. They're being subjected to curriculum that is not appropriate for them and teaching materials that are not appropriate them," she said.

Polk County schools issued a statement that said:

"We understand her frustration over trying to delicately balance mandates, other instructional priorities and most importantly, the needs of each child. As the State of Florida moves forward on accountability, we hope the process is thoughtful, equitable and balanced."

Bradshaw said she understands some standardized testing is necessary but she also disagrees with "high stakes" testing that's tied to school funding and teacher pay.

She said she's getting responses to her letter from across the country.

"The messages I'm receiving aren't just from teachers. They're from parents who say, "I see it every day. My kindergartner hates school," she said.

Bradshaw is involved with a group called, The Opt Out Florida Network which is against test-based school reforms.

She said she would go back to teaching in public schools if the testing process was changed.