Measure, estimate, compare, add, and find differences between whole-number lengths using equal nonstandard units, centimetres, and metres, choosing appropriate units and explaining why consistent units are necessary. Compare and measure mass and capacity with nonstandard units, balances, grams or kilograms, and millilitres or litres, while informally comparing temperatures as hotter, cooler, or about the same. Read clocks to the hour, half hour, quarter hour, and five-minute intervals, distinguish a.m. and p.m., sequence events, find elapsed time in whole hours, read calendars, and solve simple measurement word problems involving consistent whole-number units.