DENVER — Hundreds of teachers descended on the state Capitol on Thursday morning, demanding more pay, better classroom funding and a fix to the retirement system.

It’s the first of two days of planned protests at the Capitol that led to several school districts to cancel classes on Thursday and Friday.

Schools in Jefferson, Douglas, Lake and Clear Creek counties are closed on Thursday because so many teachers called out to take a personal day to attend the rally and protest.

With not enough substitutes, the districts decided instead to cancel classes, affecting about half of the student population in the state.

Teachers and administrators tried to make it easier for parents, pairing Thursday’s walkout with Take Your Child to Work Day.

Similar protests have happened in Arizona, Oklahoma and Kentucky.

The teachers plan talk to legislators, do a grade-in and showing them all they do on a daily basis.

Lawmakers have agreed to give schools their largest budget increase in a decade, but teachers say it’s not enough, that it hasn’t made up ground lost during the Great Recession and because of the Taxpayer Bill of Rights that limits spending.

Lawmakers can’t raise taxes without getting voter approval.

The Colorado Education Association is pushing a November ballot initiative to raise taxes on people who make more than $150,000 a year and on corporations.

A larger rally is scheduled for Monday afternoon. More teachers will join in a walkout that will close several more districts on Friday.