Time and speed

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Welcome to maths

Need: 

• Book open on p. 114
• Notebook open on an empty page (with a margin)
• Pen 
• Pencil (+sharpener and eraser)
• Geo triangle

Follow the steps

• Timer? Use it, so you can see how much time it will take you.
• A 'hotspot'? Click on it and get extra information or the answer.
• Always write the calculations and answer in your notebook as well.
• It is easier when you use your phone, because you need to take pictures. 
• Mind the notation of your answers --> 0.25 dm and not 0,25 dm or 0.25dm

This is a hotspot

It can have a different picture. Click on it and it will give you extra information or answers. 

Make a note and copy on your PIF list

unit = eenheid

time = tijd

convert = omrekenen

is equal to = is gelijk aan 

speed = snelheid

distance = afstand

travel = afleggen

Done? 

Read 'Time' and 'Speed' on p. 114. 

You will get a question afterwards

Goal

• I can 'Perform calculations with time and speed'
• I can 'Write down calculations in a short and formal way'
• I can 'Check my work'

Read 'Time' and 'Speed' on p. 114 before you continue.  

You will get a question afterwards

Which are right? Choose one

1. 0.7 hours = 70 minutes
2. 2.5 h = 2 h 30 min
3. 4.3 h = 270 min
4. 3.4 hours = 204 minutes

How many minutes are there in one hour? Look on p. 114 for the rules.

Write down the unit as well, so not just 20, but 20 minutes. 20 minutes is not the right answer :-)

How many seconds are there in one hour?
Write down a 'calculation + answer'. So
for instance
30 * 20 = 600 seconds

See p. 114

• How many seconds go into a minute? 
• How many minutes go into an hour?
• So how many seconds go into an hour? You need to multiply ... x ... = seconds

Calculate which date it is 15 days from now.
Extra challenge: Which date was it four weeks earlier?
And five weeks?

See p. 114

• 1 week = 7 days, so 4 weeks = 7* 4 = .... days

Calculate the average speed in km/h for..
...a car that travels 560 km in 7 hours.
...a cyclist that rides 104 km in 4 hours.
...a pedestrian that walks 15 km in 3 hours and 20 minutes.

See p. 114

• Divide the number of km by the number of hours. 
• 1 h = 60 m , because 1* 60 = 60 
• 0.5 h = 30 m, because 0.5*60 = 30
• So 0.2 h = 0.2 * 60 m = 12 m 

1. different answer
2. 80 ; 26 ; 4.5 km/h
3. 80 ; 21 ; 4.5 km/h
4. 80 ; 26 ; 4.7 km/h

How many minutes is 2.75 hours?
Extra challenge: How many seconds are there in 10.7 minutes?

Write down both answers + calculation in your notebook. Give only the answer of the first question here, so .... minutes.

Which steps do I need?

• Always multiply with 60 from hours to minutes, so 0.5 h = 0.5*60m = 30 minutes
• Always multiply with 60 from minutes to seconds, so 2 m = 2*60s= 120 seconds. Or 0.3 minutes -> 0.3*60 = 18 seconds

Work on...

• exercises 9, 10, 11, 12, 13 and 14 on p. 115
• Check your work after 8 minutes with a different colour
• Copy HW in your planner
• HW: Do ex. 9, 10, 11, 12, 13 and 14 on p. 115
• Continue with working on the exercises 

Next lesson

• You have finished and checked your homework 
• We will work on Perimeter and area