Working With Lengths Viki, Janina, Uli, Celina und Corbi Friday, 13th of March 2015

Contents Introduction: Learning ObjectivesUli Main 1: Adding, Subtracting, Multiplying and Dividing with LengthsViki Main 2: PerimetersJanina Main 3: Word ProblemsCelina Review: Lessons learnedCorbi

Working with lengths

Main 1:Addition and Subtraction We will talk about working with lengths! Maybe you already know what I am going to „teach“ you but lets start… First of all you need to convert e.g. cm  m No matter which calculation you have to do: Do it with the same unit! Then you just need to add and/or subtract like you do with normal numbers

Main 1: Multiplication and Division Now, multiplying and dividing is almost the same: Convert e.g. m  km Then just multiply and / or divide like you do with normal numbers! I hope now you know how to do the four operations with lengths !

Main 1: Addition and Subtraction A Street is built and so far 24,849 m long. 3,46 m more are finished today! How long is the street now? 24, ,46 28,309

Main 1: Addition and Subtraction A cat sits on a branch that is 2,55 m high. Ina is 1,42 m when she puts her arm up she comes 34 cm over her haid. She gets a ladder that is 70 cm tall. Can she help her cat? Convert: 1,43 m = 143 cm2,55 m = 255 cm + 34 cm + 70 cm 247 cm

Main 1: Multiplication and Division Jenny has a Garden. It is 10 m long and 5 m wide! How big is her Garden? 10 x 5 = 50 m² Note: If you multiply two length of different directions the result is m².

Main 1: Multiplication and Division A 1,80 m long wood stick gets cut down into pieces of 45 cm. How much pieces do you get? Convert: 1,80 cm = 180 cm 180 : 45 = 4

Main 2: Perimeter Janina will present this topic with the ‘‘White Boards‘‘

Main 3: Word Problems Question 1: Mr. Greenbird lives in Coconut Grove Island and wants to build a fence around his garden, to protect his purple palm tree from wild animals. But, he wants to install a garden gate that is 127cm wide and plant a hedge with a length of km at the property line (Grundstücksgrenze). How many meters of fence does Mr. Greenbird need if each side of the garden is 4.13m long?

Main 3: Word Problems Calculation method. How many meters of fence does Mr. Greenbird need if each side of the garden is 4.13m long?

Main 3: Word Problems Solution 1: the perimeter of the garden is: 4 x 4.13m = 16.52m. convert the garden gate in m: 127cm = 1.27m and the hedge in m: km = 3.93m add the fixed elements: 1.27m m = 5.2m subtract the fixed elements from the perimeter: – 5.2m = 11.32m Answer: Mr. Greenbird needs 11.32m of fence. How many meters of fence does Mr. Greenbird need if each side of the garden is 4.13m long?

Main 3: Word Problems Question 2: Harry wants to build three picture frames. The lengths of these frames should be 180mm each and the width should be 13cm each. In the building supply store (Baumarkt), a ridge (Leiste) has a length of 2.40m. Calculate: 1. How many cm of ridge does he need to build 3 frames? 2. How many cm of the ridge(s) are left?

Main 3: Word Problems Calculation method. 1. How many cm of a ridge does he need to build 3 frames? 2. How many cm of the ridge(s) are left?

Main 3: Word Problems Solution 2: convert the length of a picture in cm: 180mm = 18cm the perimeter of a picture is: 2 x 18cm + 2 x 13cm = 62cm the total perimeter of all pictures is: 62cm x 3 = 186cm convert the length of the ridge in cm: 2.4m = 240cm subtract the total perimeter from the length of the ridge: 240cm – 186cm = 54cm Answer: a) he needs 186cm of ridge and b) 54cm of the ridge are left. 1. How many cm of a ridge does he need to build 3 frames? 2. How many cm of the ridge(s) are left?

Main 3: Word Problems Question 3: A square with a perimeter of 0.4 m has been cut in half. Both halfs were put next to each other to form a rectangle (see picture below). How long is the perimeter of the rectangle in cm? a) 32cm b) 40cmc) 44cmd) 48cme) 50cm

Main 3: Word Problems Calculation method. How long is the perimeter of the rectangle in cm? Answer: ? a) 32cm b) 40cm c) 44cm d) 48cm e) 50cm

Main 3: Word Problems Solution 3: convert m in cm: 0.4m = 40cm the side lenghts of the square is: 40cm : 4 = 10cm the perimeter of the rectangle is made up of 4 complete sites and of 2 half sites: 4 x 10cm+ 2 x 5cm = 50cm Answer: e) is correct - the perimeter of the rectangle is 50cm. How long is the perimeter of the rectangle in cm? Answer: ? a) 32cm b) 40cm c) 44cm d) 48cm e) 50cm

Review: Lessons learned Corbi will present the review Uli & Corbi will hand out worksheets