Decimal numbers – Grade 8 and 9 Calculations
Do the calculations to practice different operations with decimal numbers.
Maths in English
Integers – Grade 8 and 9 Calculations
In this video you will have the opportunity to do specific calculations and whereafter it will be explained. Do not hesitate to refer back to our previous videos on integers if you cannot remember how to do the calculations. Remember that you should always apply the order of operations (BODMAS).
Multiplication of decimal numbers
When you need to multiply decimal numbers by a multiple of 10 (e.g. 10, 100 and 1 000), do not just “move the comma”. First you have to understand what you are doing. E.g. 1,12 x 100. You can write 1,12 as 112 hundredths (as a common fraction) and when you multiply 112/100 by 100, the…
Division of Decimal Numbers
When you do division of decimal numbers with natural numbers, follow the long division method. Just keep track of when you are “crossing” the decimal symbol. Remember that you should not have a remainder when dividing decimal numbers with natural numbers, as the place values on the right-hand side of the comma already indicate remainders….
Multiplication and Division of Integers
Have you ever wondered why 3 x -2 = -6? Or in other words, why a positive integer multiplied by a negative integer result in a negative integer? Maybe you also thought of why a negative integer multiplied by a negative integer result in a positive integer, such as -3 x -3 = 9. If…
Determining LCM and HCF with prime factors
How can you determine the LCM of two large numbers such as 36 and 225? With the help of those numbers’ prime factors. When you determine the product of the prime factors of 36 as 22 x 32 and the product of the prime factors of 225 as 32 x 52, you can determine the…
