This content is not available from your geographic area.
Log in

L'addition des dizaines entières

S1 E19
·
2018

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 tens and adding the 0 of the units. This is the same technique that is used for subtraction and doubles.

Levels:
Élémentaire 2e année 3e année 4e année
Subjects:
Mathématiques Nombres
Skills:
Apprentissage autonome Pensée critique Résolution de problèmes
French level:
A2 : Intermédiaire ou de survie B1 : Seuil
Subscription
play_circle

E33 : Débuter les soustractions

6 min 28 s
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…
Subscription
play_circle

E34 : Distinguer droite et gauche

8 min 46 s
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…
Subscription
play_circle

E35 : Divisions posées sans reste

5 min 26 s
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.
Subscription
play_circle

E36 : Effectuer des additions en appui sur 10

7 min 27 s
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.
Subscription
play_circle

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

4 min 49 s
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.
Subscription
play_circle

E38 : La division

4 min 42 s
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…
Subscription
play_circle

E39 : La symétrie axiale

5 min 49 s
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…
Subscription
play_circle

E40 : Le périmètre

7 min 42 s
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…
Subscription
play_circle

E41 : Mathématique - Le sens des multiplications

3 min 12 s
This lesson is about multiplication. Master Lucas explains what multiplication is for and how it works.
Subscription
play_circle

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

6 min 2 s
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…
Subscription
play_circle

E43 : Mathématique - Les additions posées sans retenues

5 min 19 s
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.
Subscription
play_circle

E44 : Les contenances L, cL, mL

9 min 51 s
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…
Subscription
play_circle

E45 : Les doubles jusqu'à 10

3 min 57 s
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…
Subscription
play_circle

E46 : Les fractions

8 min 4 s
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.
Subscription
play_circle

E47 : Les heures pleines

4 min 48 s
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…
    Levels:
    Élémentaire 2e année 3e année 4e année
    Subjects:
    Mathématiques Nombres
    Skills:
    Apprentissage autonome Pensée critique Résolution de problèmes
    French level:
    A2 : Intermédiaire ou de survie B1 : Seuil