number problem-solving activities
Difference and Product
Two whole numbers
D9: Two decimal
Two small numbers are generated, their sum, difference
and product are worked out.
Hide the two numbers, can you work out what they are
from their sum, product and difference?
Click on 'change' to generate two more numbers.
Hide the product, work out the two numbers from their
sum and difference.
the odd or even labels: is it possible to say whether
a sum, product or difference will be odd or even?
D36: Sum puzzle
Write a number in each circle so that the number in each
square equals the sum of the two numbers on either side
of it. There are many possible solutions for the square
arithmagon. The answer sheet will give one set of solutions.
The three numbers on each side of the triangle must add
up to the red target number.
are written in code. The letters A to J each stand for a
digit 0 to 9. Work out what digit each letter stands for
and what the 'sum' is.
1 times tables 2 to 10
2 times tables 11 to 20
4 half of . . .
6 number bonds
activity can be used as an interactive whiteboard game
played against the clock.
in a blue rectangle next to a letter in the side panel
and then click on the number you think the letter represents.
Click on the 'check' button to see how many you've got
right. The clock can shown or hidden.
Press numbers'1, 2, 3 . . . 0' on your keyboard to show
each answer in turn.
Press the space bar to show all the answers.