Sorting Numbers

 

 

1. Arrange the digits 1-9 in a line so that each pair of adjacent digits differs by either 2 or 3.
2. Arrange the digits 1-9 in a line so that each pair of adjacent digits sums to a prime number.
3. Now arrange the digits 1-9 in a line so that each pair of adjacent digits (when read as a two-digit number) appears in the times tables from 1 × 1 up to 9 × 9.

 

 

 

        Source: Katie Steckles, The New Scientist

Interesting root problem

 

 

Number Strips

via @mathequalslove
 

Proving x^0=1

 

This belongs to one of my students. 

She came up with a better explanation than mine : )

 

What do you know about numbers?

 

Number Patterns

There are different number patterns on the following number grid. Can you find them all?

Ulam Spiral

Start from 1 and wrıte numbers until 100 as a spiral.

This is called a Ulam spiral. It is devised by a mathematician Stanislaw Ulam in 1963. 

What do you observe?

An easy arithmetic task

What comes next?

Problem 110: Fathers and Sons

My father is 4 times as old as I am.

5 years from now, he will be 3 times as old as my age.

15 years later, he will be 2 times as old as I will be.

How many years ago, was his age 6 times as old as I was?

Problem 83: Jersey Numbers 2

https://www.bbc.com/news/world-asia-44791998

Three footballers were having a chat after the training. Having a keen interest in numbers, one of them said:

 -“You know if I square your jersey numbers, and then subtract one from the other, the difference will give my jersey number.”

Others were impressed with this, and they also decided to find mathematical properties of their jersey numbers. The second player said:

-“The number on my jersey is the difference of your jersey numbers.”

It was the turn for the third player. He said: 

-“The numbers on your backs are prime numbers.”

Can you find the jersey number of each player?

Rich Tasks 28: Number Gossip Project

Go to Tanya Khovanova's lovely Number Gossip webpage. Choose a number and prepare a short presentation about it.

You can see the meanings of number properties from here:

Beautiful Gifs 7: Binary System

Rich Task 21: Number Sets