Topicm3b4c868563f1ca67_1528449000663_0Topic

Dividing the decimal fractions by the natural numbers

Levelm3b4c868563f1ca67_1528449084556_0Level

Second

Core curriculumm3b4c868563f1ca67_1528449076687_0Core curriculum

V. The operations with the common and decimal fractions. The student:

2) adds, subtracts, multiplies, divides the decimal fractions by mental calculation (in the simplest operations), in writing or using the calculator (in the difficult ones);

8) does the operations with the decimal fractions using his own, proper strategies or using the calculator.

Timingm3b4c868563f1ca67_1528449068082_0Timing

45 minutes

General objectivem3b4c868563f1ca67_1528449523725_0General objective

Doing the simple operations of mental calculation or more difficult ones in writing and using these abilities in practical situations.

Specific objectivesm3b4c868563f1ca67_1528449552113_0Specific objectives

1. Mental division of decimal fraction by the natural numbers.

2. Written division of decimal fraction by the natural numbers.

3. Communicating in English; developing mathematical and basic scientific, technical and digital competences; developing learning skills.

Learning outcomesm3b4c868563f1ca67_1528450430307_0Learning outcomes

The student:

- does the mental division of the decimal fraction by the natural numbers,

- divides the decimal fractionsdecimal fractionsdecimal fractions by the natural numbers using written method.

Methodsm3b4c868563f1ca67_1528449534267_0Methods

1. Brainstorming.

2. Situational analysis.

Forms of workm3b4c868563f1ca67_1528449514617_0Forms of work

1. Individual work.

2. Pair work.

Lesson stages

Introductionm3b4c868563f1ca67_1528450127855_0Introduction

Each student brings the calculator for the lesson.

The students revise the written division of the natural numbersnatural numbersnatural numbers and the division of the decimal fractions by 10, 100 and 1000.

Procedurem3b4c868563f1ca67_1528446435040_0Procedure

The teacher introduces the topic of the lesson: dividing the decimal fractionsdecimal fractionsdecimal fractions by the natural numbersnatural numbersnatural numbers.

The students work individually using their computers. They are going to analyse the slideshow concerning the mental division of the decimal fractions.

[Slideshow1]

Discussion:

What method can be used to calculate the quotationquotationquotation of the decimal fraction by the natural number?

The students can come up with the following conclusion:

- To divide the decimal fraction by the natural number we do the division first, ignoring the decimal point. We add the decimal point in the result.  

Using the gained information the students divide the decimal fractionsdecimal fractionsdecimal fractions by the natural numbersnatural numbersnatural numbers on their own. Then, in pairs they compare the results.

Task 1

Calculate mentally.

a) 1.44 : 12

b) 0,039 : 3

c) 68.4 : 2

d) 0,0075 : 5

The students work individually using their computers. They are going to analyse the slideshow concerning the written division of the decimal fractions.

[Slideshow2]

Discussion:

What method can be used to divide the decimal fractions by the natural number using the written method?

The students can come up with the following conclusion:

- To divide the decimal fraction by the natural number we do the division first, ignoring the decimal point. Next, we place the decimal point in the result just above the decimal point of the decimal fraction which is divided.

Using the gained information the students divide the decimal fractions by the natural numbersnatural numbersnatural numbers on their own. Then, in pairs they compare the results.

Task 2

Calculate using the written division:

a) 738.35 : 5

b) 0,1048 : 4

c) 9.123 : 3

Task 3

Ann has invited four people for her birthday. She decided to make the fruit salad, so she has bought 0,25 kg of peaches, 0,2 kg of pineapples, 0,22 kg of bananas, 0,55 kg of apples and 0,15 kg of yoghurt. How many grams will one portion of the salad weigh if Ann divides it into identical portions for herself and all her guests?m3b4c868563f1ca67_1527752263647_0Ann has invited four people for her birthday. She decided to make the fruit salad, so she has bought 0,25 kg of peaches, 0,2 kg of pineapples, 0,22 kg of bananas, 0,55 kg of apples and 0,15 kg of yoghurt. How many grams will one portion of the salad weigh if Ann divides it into identical portions for herself and all her guests?

An extra task:

Kate has paid 11.70 PLN for 45 dag of ham and Marcin has paid 17.50 PLN for 7000 g of ham. Which ham was more expensive and how much more money one should pay per kilo?

Lesson summarym3b4c868563f1ca67_1528450119332_0Lesson summary

The students do the summarising tasks.

Then they sum up the class drawing the conclusions to memorise:

- To divide the decimal fraction by the natural number we do the division first, ignoring the decimal point. Next, we place the decimal point in the result.m3b4c868563f1ca67_1527752256679_0- To divide the decimal fraction by the natural number we do the division first, ignoring the decimal point. Next, we place the decimal point in the result.

Selected words and expressions used in the lesson plan

decimal fractionsdecimal fractionsdecimal fractions

natural numbersnatural numbersnatural numbers

quotationquotationquotation

mental quotationmental quotationmental quotation

written quotationwritten quotationwritten quotation

smaller numbersmaller numbersmaller number