Les unités et les dizaines

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…

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…

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…

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

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…

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

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…

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. …

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…

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.

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…

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…

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…

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…

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.