If you put three beads onto a tens/ones abacus you could make the numbers 3, 30, 12 or 21. What numbers can be made with six beads?
Lee was writing all the counting numbers from 1 to 20. She stopped for a rest after writing seventeen digits. What was the last number she wrote?
I am less than 25. My ones digit is twice my tens digit. My digits add up to an even number.
This activity has been adapted from one of BEAM's Maths of the Month resources.