# 6.4 Calculating with letters

Just as you can calculate with numbers, you can also do this with letters. The only big difference is that a numbers represents only one value where a letter can represent a whole group of numbers. In video 1 we will explain you the difference between calculating with numbers and doing so with letters. In video 2, 3 & 4 we will show you how to add up letters and how to multiply letters. To give you an overview, we will put the operations multiply and add next to one another and compare them in video 5.

Because exercise 52 deals with area and perimeter of a right-angled shape, we included some extra video\’s on area and perimeter. You can review these subjects in review 1 & 2.

• Video 1: Sum of terms – adding up letters
• Video 2: Simplifying products
• Video 3: Simplifying products – an approach
• Video 4: Like terms
• Video 5: Collecting like terms
• Video 6: multiplication & addition of letters – an abstract
• Video 7: Letters & the order of operations
• Video 8: The perimeter & area of right-angled shapes
• Video 9: The perimeter & area of right-angled shapes with letters
• Review 1: What is area?
• Review 2: What is perimeter?

#### One thought on “6.4 Calculating with letters”

1. ###### Tessa

hello,

video 6 until 8 donn’t stand in de video list. only 12345review1review2