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Maître Lucas - Mathématiques

Lire les secondes

S1 E58

·

2018

We meet again for a new video on reading the time with the reading of the seconds. After having mastered the reading of full hours and minutes, the students discover the seconds. They learn that one minute contains 60 seconds and that the seconds hand must therefore make a complete turn to make one minute. The lines used to read the seconds are the same as those used for the minutes. The exercises allow them to reinvest what they have seen in the video and to memorize it.

Levels:

Élémentaire 2e année 3e année 4e année

Subjects:

Mathématiques Sens de l'espace

Skills:

Apprentissage autonome Pensée critique Résolution de problèmes

French level:

A2 : Intermédiaire ou de survie B1 : Seuil

Episodes (49)

E18 : Additionner 3 nombres

After having mastered two-number addition, students can discover three-number addition. The first technique proposed is linear addition starting on the left and going to the right. Next, I suggest combining the numbers to form doubles and facilitate the calculation. This procedure requires that the doubles be well mastered so that…

E19 : L'addition des dizaines entières.

This video discusses addition and subtraction of whole tens. When students have studied numbers up to 100, they have also learned some calculation strategies. These strategies can work but are not always effective. So I propose a technique that relies on the tens in order to do the calculations more quickly. It involves adding the…

E20 : Additionner et soustraire des nombres décimaux

After understanding what a decimal number is, students discover how to perform addition and subtraction with decimal numbers. The element to remember is the alignment of the commas and therefore the units, hundreds, tenths, hundredths, etc. When the alignment is well done, the techniques of addition and subtraction remain the same…

E21 : Les nombres jusqu'à 10

This video is about writing numbers from one to ten in letters. The objective is to recognize and write numbers in letters.

E22 : Additions posées avec retenues

This video is about addition with a carry. It is preferable to have a good knowledge of addition without a carry before starting this new concept. I use the representation of tens and units in the form of cubes in order to concretize the addition of a ten. Indeed, holding is often abstract and it is therefore necessary to use concrete…

E23 : Les aires

This video focuses on measuring in square meters. The square meter is the unit of measurement for areas. And the area measures the surface.

E24 : Calcul de durée

In this video, students learn how to calculate a time between two points in time. Using real-life situations, students learn two strategies for calculating time. The first technique is to go through the nearest full hours. In three steps, it is possible to find a duration. From the beginning of an event, go to the next full hour and…

E25 : Centaines, dizaines, unités

Dans cette vidéo, je propose de revenir sur les centaines en s'entraînant à les lire et à les écrire. Tout d'abord, je rappelle ce que sont les unités et les dizaines. Ensuite, je propose d'illustrer une centaine par un bloc rouge de 10 dizaines afin de se rendre compte des quantités et d'éviter les confusions. …

E26 : Comparer des longueurs

The purpose of this video is to introduce students to length comparison (big, small, short, long). The first step is to make a direct comparison by approaching the objects and aligning them on one side. The direct comparison can be done with the naked eye. If the objects are too far apart, it is necessary to use an intermediate object…

E27 : Comparer des masses

This video introduces the concept of mass (to be distinguished from weight) and how to compare them. They discover the Roberval balance and how it works. The exercises proposed allow them to find the heaviest and lightest objects. They also ask to place objects according to the position of the scale.

E28 : Comparer des nombres entiers

Comparing and ordering are important steps in number manipulation. This video aims to teach some techniques for comparing numbers based on the concepts of tens and units. The idea is to start with a comparison of tens and then compare the units if necessary. This video also reminds you how to use the comparison sign and what the…

E29 : Comparer et ranger les nombres décimaux

After making the connection between decimal fractions and decimal numbers, this video gives techniques for comparing and ordering decimal numbers. The first step is to compare the whole numbers and then, in case of equality, to compare the decimal numbers (tenths, hundredths, thousandths, etc.). The technique remains the same for…

E30 : Comparer et ranger les nombres jusqu'à 10

Comparing and ordering are important steps in number manipulation. The purpose of this video is to introduce students to number comparison by first focusing on quantities. This way, students can make direct comparisons between several objects. Gradually, I propose only the numbers. Then, I give a technique for arranging numbers in…

E31 : Comparer et ranger les nombres jusqu'à 19

Comparing and ordering are important steps in number manipulation. This video aims to teach some techniques for comparing numbers based on the concepts of tens and units. This way, students can realize that for numbers greater than 10, it is possible to compare only the units. I first suggest comparisons with the help of the cubes and…

E32 : Débuter les additions

This video is an introduction to addition. The children understand the meaning of addition (add) and the meaning of the + sign. A few exercises help to familiarize them with the calculations. We also discuss techniques that children can use: fingers, cubes (or other objects), memorizing one of the numbers, the numerical frieze.

E33 : Débuter les soustractions

This video is an introduction to subtraction. Children understand the meaning of subtraction (remove or compare) and the meaning of the - sign. A few exercises are used to familiarize themselves with the calculations. Techniques that children can use are also introduced: fingers, cubes (or other objects) and the number line. It is…

E34 : Distinguer droite et gauche

Distinguishing between the right and left hand is a learning process that takes time, practice and cognitive maturation. Generally, children rely on their dominant hand (especially the writing hand) to distinguish the left hand from the right hand. I also suggest in the video to draw colored dots on each hand in order to distinguish…

E35 : Divisions posées sans reste

This video is an introduction to posed division. It is about understanding the concepts of dividend, divisor and quotient. The students learn how to pose division with a one-digit divisor. Euclidean division with remainder will be the subject of another video.

E36 : Effectuer des additions en appui sur 10

The purpose of this video is to do addition up to 20 with the help of the 10. This means that when doing an addition like 8+4, we break down the 4 to make 8+2+2 in order to go after the 10. This technique will be very useful later on when using the other tens.

E37 : Figures géométriques : Carré, rectangle, triangle, rond

In this video, students will learn to recognize geometric shapes (square, rectangle, triangle, round) based on their characteristics (number of sides). They recognize these shapes regardless of size or orientation. Conversely, the characteristics are given and the students must recognize the figure.

E38 : La division

The purpose of this video is not to do actual division, but rather to introduce students to fair sharing. Master Lucas proposes different concrete sharing situations that the students should know and that they can reproduce. He also makes reference to groups that allow for a link with multiplication: with 6 I can make 2 groups of 3…

E39 : La symétrie axiale

With this video students can take their first steps in symmetry. The idea is to understand what axial symmetry is by using folds. To begin, Master Lucas suggests folding a sheet of paper to obtain a line and painting on one side, then folding the paper again to obtain a symmetrical drawing. The fact of folding the sheet makes it…

E40 : Le périmètre

In this video students can discover the concept of perimeter. They learn that the perimeter is the sum of the sides of a geometric figure. To facilitate the calculation of the perimeter of a square and a rectangle, there are two formulas: rectangle - P = (L+l) x 2 (be careful not to forget the parentheses because of the priorities of…

E41 : Mathématique - Le sens des multiplications

This lesson is about multiplication. Master Lucas explains what multiplication is for and how it works.

E42 : Les additions et soustractions en ligne jusqu'à 20

The purpose of this video is to master several techniques for performing calculations to 20. Children understand the meaning of addition (add) and the meaning of subtraction (remove). They also recognize the symbol for addition (+) and subtraction (-). Several techniques are then used: counting on their fingers, moving forward or…

E43 : Mathématique - Les additions posées sans retenues

In this video, students learn how to add numbers in rows and columns with no holds. The technique used is to add the units and then the tens. For the addition, it is specified that it is necessary to put the units under the units and the tens under the tens. Several exercises are proposed at the end to assimilate the concepts.

E44 : Les contenances L, cL, mL

The objective is to know the units of measurement of capacity (hectoliter, decaliter, liter, deciliter, centiliter, milliliter) and to estimate measurements of capacity (e.g., to know that we do not use hL to measure the capacity of a coffee spoon). Next, I suggest using a table to convert measurements. At this point, we are only…

E45 : Les doubles jusqu'à 10

The objective of this video is to recognize a situation where there is a double. I chose to use dice to facilitate the visualization of the double and then to recognize them in calculations and finally simply with the words 'the double of...'. The proposed calculations make it possible to start memorizing, but it will not be…

E46 : Les fractions

This video allows you to discover the notion of simple fraction. It is about discovering fractions from an everyday situation. The students have probably already talked about the notion of half and quarter and they discover how to represent them (numerator and denominator). They learn how to use fractions to divide.

E47 : Les heures pleines

This video provides an opportunity to discuss reading full or battery hours with your children. I indicate that the large hand is used to show the hours and the small one the minutes. I suggest a color code to make it easier. I indicate that the minute hand should stay on 12 in order to make the battery hours. Then, the students just…

E48 : Les maisons d'additions : mémoriser les calculs

After understanding the meaning of addition, children begin to memorize certain calculations. This video is a fun way to review all the additions up to 10. Under the roof of each house, I put circles like in the Singapore method. This way, children realize that a quantity contains several equations and they can be added together to…

E49 : Les multiplications posées à un chiffre

This video corresponds to the following mathematical skill: 'To know and implement an algorithm of calculation posed to carry out a multiplication'. It aims at mastering a technique to find the answer of a multiplication. Through animations, I tried to explain the process so that it can be reproduced.

E50 : Les nombres de 69 à 99

After having well memorized the sequence of numbers up to 69, I propose this video to understand the functioning of the numbers from 69 to 99. It is a question of memorizing the names of the numbers and also to understand why 70 is called seventy and 90, ninety. To do this, I suggest using additions such as 60+14=74 in order to…

E51 : Les nombres jusqu'à 5

This video deals with numbers and quantities up to 5. The objective is to quickly recognize the writing of numbers and their different representations (fingers, dice, tokens). Students start these exercises by counting one by one. With practice, they will be able to recognize quantities directly without going through the counting…

E52 : Les solides

In this episode, Master Lucas presents the solids. He also emphasizes their characteristics: vertices, edges and faces.

E53 : Les unités et les dizaines

All mathematical concepts become simpler when the tens and units are mastered. Comparing numbers, ordering, adding, subtracting, etc., all rely on this knowledge. In this video I have represented the units by blue cubes and the tens by green bars. The children are led to start from the cubes to find the numbers and vice versa.

E54 : Lire l'heure

After posting five videos on telling time, I wanted to put them all together in one video for students who want to review everything. It is important to know that learning to tell time takes place over several years. So I don't recommend starting from scratch and seeing everything at once. It is better to be progressive in…

E55 : Lire les heures : moins 10, moins le quart

We are coming up on the part of reading the time and the least obvious. Thus, it is better to master the other skills before approaching this video. This means reading the minutes before the next hour: minus twenty-five, minus twenty, etc. Managing multiple pieces of information is an obstacle for many students: they have to locate…

E56 : Lire les heures de l'après midi

After learning how to read the full hours, this video discusses the afternoon hours. I explain that the little hour hand makes two turns in a day, so I show a dial with the hours from 13 to 24. Different exercises allow you to gradually associate the morning and afternoon hours.

E57 : Mathématique - Lire les minutes

After learning to read the full hours and afternoon. This video aims to learn how to read the minutes. I explain that an hour is composed of 60 minutes that we indicate by noting the numbers from 5 to 5. The big hand shows the minutes when the small one indicates the hours. To read the time, we start with the hours, then the minutes…

E58 : Lire les secondes

We meet again for a new video on reading the time with the reading of the seconds. After having mastered the reading of full hours and minutes, the students discover the seconds. They learn that one minute contains 60 seconds and that the seconds hand must therefore make a complete turn to make one minute. The lines used to read the…

E59 : Mesurer avec une règle (cm, mm)

This video is about using the ruler to measure lengths. I introduce the concept of centimeters again and the students can discover the concept of millimeters. The aim is to learn how to position the ruler so that the measurement starts at 0. I also show how to draw lines of different lengths.

E60 : Mesurer des masses

After comparing masses with a Roberval balance, children discover in this video how to measure in grams and kilograms. In particular, it is described how to measure using Roberval's balance and weights (making sure the balance is balanced). Several exercises reinforce this concept. I have also included exercises to help children…

E61 : Multiplier des nombres décimaux

Once students have mastered decimal numbers and multiplication, they can begin to multiply decimal numbers. The idea is to learn to position the numbers before starting the calculation. To do this, simply ignore the decimal point at first and simply perform the multiplication. When it is done, you have to count the number of digits…

E62 : Nombres décimaux et fractions décimales

Decimal fractions and decimal numbers describe new numbers to compensate for the inadequacy of whole numbers, especially for measuring length. The graduated ruler is one of the first encounters students have with decimal numbers. This video is an introduction to decimal fractions and decimal numbers. A decimal fraction is a division…

E63 : Se repérer sur un quadrillage

Students learn to find their way around a grid by knowing the concepts of column, row and square. They cross the columns and rows to find the box and code it as (A,1). Conversely, they must locate a square based on the location code.

E64 : Soustractions posées sans retenues

This video aims to teach you how to do subtraction without carryovers. The idea is to understand that subtraction is only to be done in certain situations (1000-980 or 100-18 are not included, for example). The students must then remember to line up the units, tens, etc. After placing the numbers with the largest above, they calculate…

E65 : Unités de longueur (cm, m, km)

After comparing lengths in direct and indirect comparison, this video discusses the units of measurement for length. We see what a centimeter, a meter and a kilometer correspond to. Students learn that it is necessary to adapt the unit of measurement to what is being measured. They also discover the tools that are useful for measuring…

E66 : Utiliser la règle

How to draw a straight line? How to hold your ruler? These are the two questions that this video will answer. It's all about positioning your fingers well on your ruler and sticking to the ruler with your pencil (well sharpened). I also show how to draw vertical lines for right and left handed people. Two cards are included with…