Reasoning, convincing and proving

There are 514 NRICH Mathematical resources connected to Reasoning, convincing and proving
More Number Sandwiches
problem

More number sandwiches

Age
11 to 16
Challenge level
filled star empty star empty star
When is it impossible to make number sandwiches?
Next-door Numbers
problem

Next-door numbers

Age
5 to 7
Challenge level
filled star empty star empty star
Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?
Mega Quadratic Equations
problem

Mega quadratic equations

Age
14 to 18
Challenge level
filled star empty star empty star
What do you get when you raise a quadratic to the power of a quadratic?
Open Squares
problem

Open squares

Age
7 to 11
Challenge level
filled star filled star filled star
This task, written for the National Young Mathematicians' Award 2016, focuses on 'open squares'. What would the next five open squares look like?
Mathdoku demonstration
page

Mathdoku demonstration

This video of Charlie and Liz solving a 6 by 6 Mathdoku may give you ideas for strategies to try.
Why dialogue matters in primary proof
article

Why dialogue matters in primary proof

In this article for Primary teachers, Ems explores three essential features of proof, all of which can be developed in the context of primary mathematics through talk.
Interactive Balance
interactivity

Interactive balance

In this simulation of a balance, you can drag numbers and parts of number sentences on to the trays. Have a play!
Purposeful Paper Folding
article

Purposeful paper folding

In this article for primary teachers, Fran describes her passion for paper folding as a springboard for mathematics.