That’s what six-year-old son of my friend and colleague Rachel Lambert told her one day when he came home from school.

That sentence has stayed with me ever since. With the wisdom that is sometimes only expressed by young children, he captured, in a few words, one of the deepest problems in mathematics education. Too many math classrooms, especially in high school and beyond, are based more on performance than learning.

Children quickly learn that their job in math classrooms is to get answers correct, as quickly as they can. But this is not effective learning. Important learning involves wondering, creating, trying out ideas, getting stuck, making connections, asking questions, and seeking patterns. Learning needs time, and students should be encouraged to think deeply, not quickly.

This matters for many reasons – one of them being that deeper learning allows students to experience real mathematics, a rich, interconnected subject full of patterns, ideas, connections, and relationships.

I watched my own children shift their focus from learning mathematics to performing. As soon as grades entered the picture, grades became their focus. Technology has not helped with this problem, as now high schoolers can check their grades every minute of every day, and they often do. Mathematics, more than any subject, traps them inside a performance cycle.

For decades, researchers have shown that what people believe about their ability changes their learning. If people think that their math ability is fixed it will damage their learning – and make every time of struggle a reason for believing they are not “math people”.

I hear fixed ability language all the time, particularly on the Stanford campus where I hear “you are so smart” every day. Families share the same ideas with statements such as: “She can’t do math - just like me” or “My son got my husband’s math brain.” These statements sound harmless but they aren’t.

When students believe that mathematical ability is fixed, every mistake or time of struggle feels like evidence they do not have it. Every difficult problem becomes a test of whether they are “smart” enough. For many students a wrong answer doesn’t mean “I find this area of mathematics difficult”, it means “I am not good at math”.

Students use mathematics, more than any other subject, to define their self-worth.

And when classrooms emphasize speed, grades, tests and constant right answers, learning becomes harder and those performance messages become stronger. Students soon start to believe the incorrect idea that some people have a “math brain” and some do not, and that the teacher’s job is to find out who has it. That is a performance culture. A learning culture is very different.

I have spent my career sharing tasks that encourage deep learning with educators and families.

I have also shared that we can all open mathematics questions to give more opportunities for depth, thinking and reasoning. Instead of asking a question that is common in math classrooms:

Find the area of a 12 feet x 3 feet rectangle.

We can ask students to find as many different rectangles as they can with an area of 24 square feet.

The first question requires a calculation. The second one invites students to visualize, to find different solutions, to see the relationship between length and width, and to ask their own questions.

The closed question asks students to perform; the open question gives students the opportunity to think and learn. A good mathematics task doesn’t ask for one single answer with one valued method, it creates space for students to notice, make conjectures, visualize, explore and discuss.

We also need to rethink mistakes and times of struggle.

In performance-oriented classrooms, mistakes are treated as something to avoid. Students become fearful of being wrong, and they only raise their hands when they are sure they are right. They stop being willing to try out ideas and stick with what they are certain of.

But mistakes and struggle are an important part of learning. When we struggle with an idea, our brains are working to make sense of something that is new. Learning should never be a passive process in which information is deposited into our minds. It involves active engagement, attention, retrieval, connection-making and the revision of knowledge. And times of struggle are the best times for our brains – they are the times when brains are forming, connecting, and strengthening pathways.

The best mathematics classrooms are those that welcome mistakes, and that display signs like these:

Sometimes a mistake contains the beginning of an important new mathematical idea. When I teach students, I share with them famous mistakes that have led to whole new branches of mathematics.

One of the most powerful forms of mathematics teaching comes from using what I call “low-floor, high-ceiling tasks”, problems that everyone can start, but that can be taken to high levels. These tasks allow students with different experiences and strengths to enter the same mathematical arena and take their thinking in different directions.

Instead of asking yourself: “Am I good at math?” ask yourself: “What mathematical journey do I want to take?” Because we are all capable of strong mathematical thinking and of taking our own mathematical journeys. Students are all different in their journey taking – some of them struggle often, some are fast but have trouble explaining their thinking, some see mathematics visually, some ask unusual questions. Their journeys are different, but their thinking is valuable and the more diverse ways of thinking are present in a classroom, the better the mathematical discussions become.

We can all play a role in helping shift mathematics classrooms from performance to learning cultures. We can share with teachers my online classes and books that help them redesign classrooms, changing them from places of pressure and speed, to places of thinking, curiosity and enjoyment. Classrooms that value questions and processes as much as answers. Classrooms that treat mistakes as opportunities for learning. And classrooms that assess students’ growth and learning, not by reducing them to grades or scores, but by giving valuable feedback from which students can learn.

Everybody – children and adults – deserve the opportunity to experience and enjoy their own mathematical journey. And Rachel’s six-year-old son was right. In math classrooms we need less answer time and more learning time.

Jo Boaler is a Stanford Professor, cofounder of youcubed and Struggly. Her most recent books are Math-ish:Finding Creativity, Diversity & Meaning in Mathematics, and Data Minds: How Today’s Teachers Can Prepare Students for Tomorrow’s World