NSW Syllabuses

# Mathematics K–10 - Stage 4 - Measurement and Geometry Time

## Outcomes

#### A student:

• MA4-1WM

communicates and connects mathematical ideas using appropriate terminology, diagrams and symbols

• MA4-2WM

applies appropriate mathematical techniques to solve problems

• MA4-15MG

performs calculations of time that involve mixed units, and interprets time zones

Related Life Skills outcomes: MALS-20MG, MALS-21MG, MALS-22MG, MALS-23MG, MALS-24MG

## Content

• Students:
• Solve problems involving duration, including using 12-hour and 24-hour time within a single time zone (ACMMG199)
• add and subtract time mentally using bridging strategies, eg from 2:45 to 3:00 is 15 minutes and from 3:00 to 5:00 is 2 hours, so the time from 2:45 until 5:00 is 15 minutes + 2 hours = 2 hours 15 minutes
• add and subtract time with a calculator, including by using the 'degrees, minutes, seconds' button
• round answers to time calculations to the nearest minute or hour
• interpret calculator displays for time calculations, eg 2.25 on a calculator display for a time calculation means $$\, 2\!\tfrac{1}{4} \,$$ hours or 2 hours 15 minutes
• solve a variety of problems involving duration, including where times are expressed in 12-hour and 24-hour notation, that require the use of mixed units (years, months, days, hours and/or minutes)
• Solve problems involving international time zones
• compare times in, and calculate time differences between, major cities of the world, eg 'Given that London is 10 hours behind Sydney, what time is it in London when it is 6:00 pm in Sydney?'
• interpret and use information related to international time zones from maps (Problem Solving)
• solve problems involving international time as it relates to everyday life, eg determine whether a particular soccer game can be watched live on television during normal waking hours (Problem Solving)

### Background Information

Calculations involving time can be made on a scientific calculator either by using fractions and decimals or by using the 'degrees, minutes, seconds' button. Students should be familiar with both approaches.

#### Purpose/Relevance of Substrand

The relevance of this substrand to everyday situations has been seen in earlier stages, as it has involved sequencing events; describing, comparing and ordering the durations of events; reading the time on analog and digital clocks (including 24-hour time); converting between hours, minutes and seconds; using am and pm notation in real-life situations; and constructing timelines. In Stage 4, students learn the very important everyday-life skills of adding and subtracting time in mixed units (both mentally and by using a calculator) and solve related problems, as well as problems involving international time zones. The ability to compare times in, and calculate time differences between, major cities and areas of the world is of fundamental importance in international travel and also in everyday and work situations, such as communicating with people in other countries, watching overseas sporting events live on television, and conducting international business.

### Language

The words 'minute' (meaning 'small') and 'minute' (a time measure), although pronounced differently, are really the same word. A minute (time) is a minute (small) part of one hour. A minute (angle) is a minute (small) part of a right angle.