Get hands-on with sums. These tough, tactile pebbles are cast from a unique and durable mix making them suitable for use across different settings including outdoors. Great for learning and practising addition and subtraction to 20 (including zero), problem solving and creating mathematical statements, they are a flexible and engaging numeracy resource. Each set includes 2 each of numbers 0-20, +, -, = and 1 each of x and ÷ (50 pebbles).