80 likes | 207 Views
Writing expressions and formulae. Writing expressions. Harriet has n pairs of shorts and some t shirts. She has three times as many t shirts as shorts What is an expression for the number of t shirts she has? 3 x n = 3n Harriet threw out half of her pairs of shorts
E N D
Writing expressions • Harriet has n pairs of shorts and some t shirts. • She has three times as many t shirts as shorts • What is an expression for the number of t shirts she has? • 3 x n = 3n • Harriet threw out half of her pairs of shorts • What is an expression for the number she threw out? • N 2
You have d sweets • Florence Williams has 4 more than you. How many does Florence have? • You give away 3 sweets to Andrew Fursey. How many do you have left? • Megan lean has twice as many as you had at the start. How many does Megan have? • Megan shares her sweets between herself and 3 friends. How many do they each get?
Annelot makes cheese, egg, ham and tomato sandwiches. S stands for the number of cheese sandwiches Anne lot makes. • Annelot makes three times as many egg sandwiches as cheese ones. How many egg ones does she make? • Annelot makes the same number of ham as cheese sandwiches. How many ham and sandwiches does she make? • Annelot makes 10 more tomato than cheese sandwiches. How many tomato sandwiches does she make • How many sandwiches does she make altogether? Write your answer as simply as possible
Writing formulae • The area of a rectangle is found by multiplying the length by the width. We can write a formula for using A for area l for length and w width • A =lw
Page 192 Exercise 11 • Write a formula for 1 a-g