An elementary school teacher asked her third grade pupils to complete the sentence 'I wish my teacher knew' in a bid to get to know them better.

But when the pupils at Doull Elementary School in Denver, Colorado, handed back their hand-written answers to their teacher Kyle Schwartz, she was shocked by the severity of their answers.

The notes, which have recently been published as a book, revealed the problems children faced with social issues such as deportation, poverty, death and absent mothers.

Revelations: Children shared their heart-breaking stories, pictured, with their teacher after being asked to complete the sentence 'I wish my teacher knew...'

Hidden lives: Elementary school teacher Kyle Schwartz asked her pupils what they would like to tell her in a bid to get to know them better

Surprised: When they handed the notes back, she was shocked at the gravity of the social issues the third grade children were faced with

Productive exercise: The teacher at Doull Elementary School in Denver, Colorado, shared her findings online and was overwhelmed by the response

Author: Kyle, pictured, has now collated her findings into a book including moving examples of the children's notes

Following the success of the exercise, she shared it online last year and the hashtag '#iwishmyteacherknew' became a hit on Twitter - inspiring other teachers to follow in Kyle's footsteps and share their results.

In her book, I Wish My Teacher Knew: How One Question Can Change Everything For Our Kids, she shares some of the most moving messages from children.

'I wish my teacher knew I don’t have pencils at home to do my homework', wrote one.

Another said: 'I wish my teacher knew that sometimes my reading log is not signed because my mom isn’t around a lot'.

Disupted home life: The notes revealed the problems children faced with social issues such as deportation, pictured

Troubled: Other problems that were creating obstacles in the children's lives included poverty, death, divorce, pictured, and absent parents

Poverty: One child, whose note is pictured, was so poor that they did not have pencils at home to do their homework

Lonely: This child said they did not have anybody to play with

Loving: One child, whose note is pictured, said their brother gets scared at night and they take care of him

One child revealed: 'I wish my teacher knew how much I miss my dad because he got deported to Mexico when I was 3 years old and I haven’t seen him in six years'.

In the book, Kyle argues that it is crucial for teachers and families to work together.

'I really want families to know how intentional teachers are about creating a sense of community and creating relationships with kids,' she wrote.

'Kids don’t learn when they don’t feel safe or valued.'

Hard-working: This child said they did not get to see their father often because he has two jobs

Health issues: This child said their cousin's medical treatment worried them

Hopes: Some of the notes, such as this one, reveal the dreams and aspirations of children

Communication: This child said they wished their teacher could speak Vietnamese

Preferences: This child said they worked better while listening to music

She said there were numerous mistakes that could have been prevented if she had known her pupils better.

As an example, she tells the story of a former pupil, Chris, who loved science.

She said she thought she was being helpful when she got him a place on a summer camp with a focus on science.

But she admitted she had no idea about his family's financial problems that meant they could not afford to take time off from work to take their son to the camp.