The document contains a series of doubling and halving calculations with numbers in categories ranging from basic facts to more complex multi-digit numbers. It includes calculations like 1 x 16, 2 x 8, 4 x 4 which double and halve basic numbers and also calculations like 8 x 32, 4 x 64, 2 x 168 which double and halve multi-digit numbers. It has sections for doubling and halving 1 digit and 2 digit numbers, 2 digit numbers, and also explores tripling, quadrupling, thirding and quartering numbers. The purpose is to investigate patterns that emerge from performing these types of calculations.