The range includes a new type of device called the Chromebit, which looks like an oversized memory stick, and turns monitors and TVs into computers when plugged into their HDMI ports.

The tech firm also revealed the cheapest Chromebook laptops to date, costing $149 (£101).

The move is likely to intensify competition with Microsoft.

The announcements came less than a day after Microsoft revealed plans to sell a new entry-level tablet-laptop hybrid of its own.

Its Surface 3 costs more -$499, and £419 in the UK for the basic model - but provides access to a wider range of software made for the Windows platform.

"This is a booming sector of the market at the moment," commented Chris Green, a tech analyst at the Davies Murphy Group consultancy.

"With the falling cost of hardware, schools are looking to families to equip kids with their own computers - the idea of BYOD [bring your own device to class].

"This has prompted manufacturers to create low-cost entry-level laptops that parents then buy for their children as well as themselves."

Google has pledged not to display ads to children that use the education-related software it provides for its Chrome platform, and does not charge manufactures to use its operating system.

But one expert said the company still hoped to financially benefit in the long-term.

"The key goal here for both Google and Microsoft is to put their brand and services out there in front of kids to build loyalty at a very early age," said Ronan de Renesse, a consumer technology expert at the Ovum consultancy.

"It's also a good way to to see whether or not to extend these types of devices to emerging markets, where they could be used outside education by people with very low disposable incomes."

For now, Google says the new Chromebooks and Chromebits will be limited to the US.

"We hope to make these widely available in the future, however we have nothing more to announce at this time," said a spokeswoman.

Stick computers

Chrome OS runs web-based software via the firm's Chrome browser and recently gained the ability to run a limited number of Android apps . The platform is designed to store most of its users' files in the cloud.

More than five million Chromebooks and Chromebase desktops were sold across the world last year, according to market research firm Gartner.

It forecasts that figure will grow to close to eight million units this year, and 16 million in 2018.

The Chromebits will be made by the Taiwanese manufacturer Asus.

Google said they would cost "less than $100" and go on sale before the end of the year.

The search firm has already had success with the Chromecast, a media streaming dongle with a similar form factor.

In recent months both Intel and Hannspree have launched Windows-powered "PC-on-a-sticks", albeit at a slightly higher cost.

Such devices require their owners to provide displays, keyboards and other peripherals, but the idea is that many people will already own them.

"People seem to love the idea of having a working computer on something no bigger than a dongle that lets them do web browsing, media streaming and other tasks on a big screen, but can be out of sight, out of mind when needed," said Mr Green.

(BBC)