1. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Revision of Level D/E Time Calculating Distance Time Distance Speed www.mathsrevision.com Calculating Speed Calculating Time Converting Hour Minutes to Decimal Time Time, Distance and Speed Problems Converting Decimal Time to Hour Minutes Time – Distance Graphs

2. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com

3. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 2.Convert 24hr to 12hr clock. 1.To revise Level D/E work on Time. Time Revision of Level D/E 1.Convert 12hr to 24hr clock. 3.Count Method to find time intervals.

4. 4-May-15Created by Mr. Lafferty Maths Dept. 230022002100200019001800170016001500140013001200 11 pm10 pm9 pm8 pm7 pm6 pm5 pm4 pm3 pm2 pm1 pmmidday 110010000900080007000600050004000300020001000000 11 am10 am9 am8 am7 am6 am5am4 am3 am2 am1 am midnight 12/24 Hour Clock To go from 12 hour clock to 24 hour clock just add 12 to the pm hours: 2000 2100 1830 2330 1620 Examples 8 pm becomes 9 pm becomes 6:30 pm becomes 11:30 pm becomes 4:20 pm becomes 3:10 pm becomes 1510

5. 4-May-15Created by Mr. Lafferty Maths Dept. 230022002100200019001800170016001500140013001200 11 pm10 pm9 pm8 pm7 pm6 pm5 pm4 pm3 pm2 pm1 pmmidday 110010000900080007000600050004000300020001000000 11 am10 am9 am8 am7 am6 am5am4 am3 am2 am1 am midnight 12/24 Hour Clock To go from 24 hour clock to 12 hour clock just subtract 12 from the hours if it is greater than 12: 8 pm 9 pm 5:30 pm 10:08 pm 8:06 pm Examples 2000 becomes 2100 becomes 1730 becomes 2208 becomes 2006 becomes 1350 becomes 1:50 pm

6. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Counting Method When working out time difference we will use the Counting Method. This method will always work. Example : Find the time difference between 08 46 hrs and 11 52 hrs 08 46  09 00 09 00  11 00 11 00  11 52 HrsMins 14 2 52 266 60 mins = 1hr 3 hrs 6 mins nearest hour hours What’s left? +

7. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Counting Method Example : Find the time difference between 02 37 hrs and 23 49 hrs 02 37  03 00 03 00  23 00 23 00  23 49 HrsMins 23 20 49 2072 nearest hour hours What’s left? + 21hrs 12mins

8. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 1 & 2 Ch10 (page 107) www.mathsrevision.com Time Revision of Level D/E

9. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com 4x 6x 120 o 70 o 4x

10. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 1.Know the distance formula. 1. To explain how to work out simple distance calculations using the distance formula. Distance Working Out Distance 2.Use the formula to work out simple distance calculations.

11. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Distance Working out Distances Imagine you were travelling in a train at a steady speed of 80km/hr. In 1 hour you travel :80 x 1 = 80 km In 2 hours you travel :80 x 2 = 160 km In 3 hours you travel :80 x 3 = 240 km Can you guess what the formula is : in symbols

12. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems Example : Liam drove from his house to the Fort William, a distance of 315 miles. It took him 3hrs. What was his average speed? Working

13. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 3 Ch10 (page 111) www.mathsrevision.com Distance Working Out Distance

14. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com

15. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 1.Know the speed formula. 1. To explain how to work out simple speed calculations using the speed formula. Speed Working Out Speed 2.Use the formula to work out simple speed calculations.

16. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Speed Working Out Speed Imagine you sailed 45 kilometres between two islands and it took 3 hours. In 3 hours you travel := 45 km In 1 hour you travel : 45 ÷ 3 = 15 km This means your speed is :15km/hr Can you guess what the formula is : in symbols

17. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems Example : Liam drove from his house to the Perth, a distance of 135 miles. It took him 3hrs. What was his average speed? Working

18. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 4 Ch10 (page 112) www.mathsrevision.com Speed Working Out Speed

19. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com x cm 4 cm

20. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria Time Working Out Time 1. To explain how to work out simple time calculations using the time formula. 1.Know the time formula. 2.Use the formula to work out simple time calculations.

21. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Working Out Time Imagine you flew 800 miles to Paris and the average speed of the plane was 200 miles/hr. To travel 200 miles takes 1 hour : To travel 800 miles takes : 800 ÷ 2 00 = 4 hours Can you guess what the formula is : in symbols

22. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems Example How long did the bus journey take if it travelled a total distance of 100 km at and an average speed of 40 km/hr. Working

23. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 5 Ch10 (page 114) www.mathsrevision.com Time Working Out Time

24. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com

25. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 1. To show the traingle method of remembering the distance, speed and time formulae. 1. Know and remember triangle method for distance, speed time problems. Time Distance Speed Mixed Problems 2. Apply triangle method to mixed problems.

26. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems D ST Simple way to remember the 3 formulae ! D=S T

27. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems Example 1 : Daniel drove from his house to the Blackpool, a distance of 135 miles. It took him 2hrs 15mins. What was his average speed? Working Time MUST be in hours format D ST

28. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems Example 2 : A racing car travelled at 50 km/hr. What is the distance covered in 6 hours ? Working D ST

29. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Speed Mixed Problems Example 1 : How long did the bus journey take if it travelled a total distance of 60 km at an average speed of 40 km/hr. Working D ST

30. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Ex6 Ch10 (page 116) www.mathsrevision.com Time Distance Speed Mixed Problems

31. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com

32. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 1. To show how to convert hours and minutes to decimal time. 1. Know that decimal time MUST be used in formulae. Hrs Mins to Decimal Time 2. Convert from hours and mins to decimal time. Converting Hrs Mins to Decimal Time

33. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Hrs Mins to Decimal Time Converting Hrs Mins to Decimal Time You should already know : Example 1 : 48 minutes to decimal is= 0.8 hr Example 2 :2hr 15 minutes to decimal is = 2.25 hr To change minutes to a decimal ‘divide by 60’

34. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Extension booklet 6E (page 41) www.mathsrevision.com Time Distance Speed

35. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com

36. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 1. To show how to convert back from decimal time to hours and minutes. 1. Know the rule for converting back from decimal time to hours and mins. Hrs Mins to Decimal Time Converting Decimal Time to Hrs Mins

37. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Hrs Mins to Decimal Time You should already know : To change minutes to a decimal time ‘divide by 60’ To convert back to and minutes we do the opposite : To change decimal time to minutes ‘multiply by 60’ Converting Decimal Time to Hrs Mins

38. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Hrs Mins to Decimal Time Example 1 : 0.7 hrs to minutes is = 42 mins Example 2 : 3.4 hrs to hours and minutes is = 3 hrs 24 mins Converting Decimal Time to Hrs Mins To change decimal time to minutes ‘multiply by 60’

39. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Now try Extension Booklet 7E (page 44) www.mathsrevision.com Time Distance Speed Converting Hrs Mins to Decimal Times

40. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. Starter Questions Starter Questions www.mathsrevision.com

41. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Learning Intention Success Criteria 1.To interpret Time – Distance Graphs. 1. Understand the term interpret. Time Distance Graph 2.Understand that the speed can be calculated from the Time - Distance Graph. Interpreting Time – Distance Graphs

42. National 4 NUM 1.2 4-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Time Distance Graph Interpreting Time – Distance Graphs