Rachunki pamięciowe na ułamkach dziesiętnych - Matematyka Szkoła Podstawowa i Gimnazjum

In this video, I show how to perform mental calculations with decimal numbers, including addition, subtraction, multiplication, and division. I teach several methods for adding and subtracting decimals: using the number line, ignoring the decimal point and correcting its position afterward, and decomposing numbers into parts. I present the rules for multiplying and dividing decimal numbers by 10, 100, and 1000, as well as methods for shifting the decimal point. I also explain how to mentally multiply two decimal numbers and how to divide, which requires first converting both numbers into whole numbers. I demonstrate how to apply these methods in practice for calculations requiring greater precision and evaluate the difficulty of using them without a calculator. TABLE OF CONTENTS: Adding decimal numbers on a number line Mental addition by shifting the decimal point Addition by breaking numbers into parts Subtracting decimal numbers on a number line Mental subtraction by shifting the decimal point Subtraction by breaking numbers into parts Multiplying decimal numbers by 10, 100, 1000 Dividing decimal numbers by 10, 100, 1000 Multiplying two decimal numbers Dividing decimals by decimal numbers Converting division of decimals into division of whole numbers CONTINUATION OF THIS VIDEO is available here: [   • Dokończenie filmu p.t. Rachunki pamięciowe...  ](   • Dokończenie filmu p.t. Rachunki pamięciowe...  ) You can find more in the following playlists: [   • RACHUNKI PAMIĘCIOWE  ](   • RACHUNKI PAMIĘCIOWE  ) [   • UŁAMKI DZIESIĘTNE  ](   • UŁAMKI DZIESIĘTNE  ) EASY ACCESS to all my math lessons is available on my website: [www.matmagwiazdy.pl](http://www.matmagwiazdy.pl) On this channel, you’ll find the complete course – 100% of the lessons – in Mathematics for Primary School, High School, and Technical School. Good luck :) Tomasz D. Gwiazda **CHAPTERS** [00:00] Adding decimal numbers on a number line [03:28] Mental addition by shifting the decimal point [05:32] Addition by breaking numbers into parts [06:58] Subtracting decimal numbers on a number line [08:53] Mental subtraction by shifting the decimal point [10:13] Subtraction by breaking numbers into parts [13:58] Multiplying decimal numbers by 10, 100, 1000 [16:31] Dividing decimal numbers by 10, 100, 1000 [18:43] Multiplying two decimal numbers [26:05] Dividing decimals by decimal numbers [29:30] Converting division of decimals into division of whole numbers