Time & Money

Time Units

Seconds, minutes, hours and days: multiply going down, divide going up.

a.m., p.m. and the 24-Hour Clock

After noon the 24-hour clock keeps counting: 1 p.m. is 13:00.

Elapsed Time

Jump to the next hour, jump the hours, then jump the minutes.

Start and End Times

Start time plus time taken gives the end time, and back again.

Calendar

30, 31 or 28: finish the month, add the whole months, then the rest.

Rupees and Paise

₹1 is 100 paise, so the two digits after the dot are paise.

Bills and Change

Each row is quantity × rate. Add the rows, then count up to the note.

Profit and Loss

Selling price above cost price is a profit, and below it is a loss.