Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?
The sum of the numbers 4 and 1 [1/3] is the same as the product of 4 and 1 [1/3]; that is to say 4 + 1 [1/3] = 4 × 1 [1/3]. What other numbers have the sum equal to the product and can this be so for any whole numbers?
Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...
How could Penny, Tom and Matthew work out how many chocolates there are in different sized boxes?
Watch these videos to see how Phoebe, Alice and Luke chose to draw 7 squares. How would they draw 100?
Is there a temperature at which Celsius and Fahrenheit readings are the same?
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
What's special about the area of quadrilaterals drawn in a square?
