Unit 6: Percents

Unit 6 –Percent of a Number

A Special Proportion… 𝐏𝐚𝐫𝐭 𝐓𝐨𝐭𝐚𝐥 = % 𝟏𝟎𝟎

Percent of a Number Example Method 1: Multiply the % by the number Method 2: Use the special proportion Step 1 – Write the percent over 100 and multiply by the number 𝟐𝟎 𝟏𝟎𝟎 ×𝟓𝟎 Step 2 – reduce if possible Step 3 – multiply x = 10 𝐩𝐚𝐫𝐭 𝐰𝐡𝐨𝐥𝐞 = % 𝟏𝟎𝟎 𝐱 𝟓𝟎 = 𝟐𝟎 𝟏𝟎𝟎 100x = 1000 100 100 x = 10 10 1 2 1

Percent of a Number Example Method 1: Multiply the % by the number Method 2: Use the special proportion Step 1 – Write the percent over 100 and multiply by the number 𝟖 𝟏𝟎𝟎 ×𝟔𝟎 Step 2 – reduce if possible Step 3 – multiply x = 𝟐𝟒 𝟓 x = 𝟒 𝟒 𝟓 𝐩𝐚𝐫𝐭 𝐰𝐡𝐨𝐥𝐞 = % 𝟏𝟎𝟎 𝐱 𝟔𝟎 = 𝟖 𝟏𝟎𝟎 100x = 480 100 100 x = 4.8 3 5

Percent of a Number Example Method 1: Multiply the % by the number Method 2: Use the special proportion Step 1 – Write the percent over 100 and multiply by the number 𝟖𝟎 𝟏𝟎𝟎 ×𝟏𝟐𝟎 Step 2 – reduce if possible Step 3 – multiply x = 96 𝐩𝐚𝐫𝐭 𝐰𝐡𝐨𝐥𝐞 = % 𝟏𝟎𝟎 𝐱 𝟏𝟐𝟎 = 𝟖𝟎 𝟏𝟎𝟎 100x = 9600 100 100 x = 96 16 6 5 1

Percent of a Number Independent Practice Use either method to find the percent of each number. 38% of 300 200% of 10 What number is 25% of 160? What number is 59% of 20? 114 20 40 11.8

Percent of a Number in Word Problems Example Of the 450 students at Miller Middle School, 38% ride the bus to school. How many students ride the bus to school? 𝐱 𝟒𝟓𝟎 = 𝟑𝟖 𝟏𝟎𝟎 100x = 17100 100 100 x = 171 students ride the bus

Percent of a Number in Word Problems Example In 2004, there were 19,396 bulldogs registered by the American Kennel Club. Approximately 86% of this number were registered in 2003. About how many bulldogs were registered in 2003? 𝐱 𝟏𝟗,𝟑𝟗𝟔 = 𝟖𝟔 𝟏𝟎𝟎 100x = 1,668,056 100 100 x = 16,681 bulldogs