170 likes | 252 Views
Friday 2/11. HW: NONE Get out last night’s HW While I am checking, log onto the computer. While waiting to log in, complete 6-2 B #1-8 in your packet! Let’s try to all be on task so we can get through percents! Guess What? We actually did almost 2 sections yesterday! Hooray for you!.
E N D
Friday 2/11 HW: NONE • Get out last night’s HW • While I am checking, log onto the computer. • While waiting to log in, complete 6-2 B #1-8 in your packet! • Let’s try to all be on task so we can get through percents! Guess What? We actually did almost 2 sections yesterday! Hooray for you!
Percents Can you find the percent of a number?
Finding the percent of a number Let’s say I wanted to find out what 80% of 35 is… First, I remember a few things: • I can solve any problem like this using a proportion or an equation. • When I set up a proportion, I always use this rule: Part over Whole: Part 80 = n Part Whole 100 35 Whole 3. Use these 3 word clues: of indicates whole is indicates part what number indicates x Write this down in your notes before you continue on! Copy the example and what the 3 words mean!
Let’s take another look: If you received a 80% on a test and there were 35 questions, how many did you get correct? STEP 1: Identify the part and whole of the problem. What is 80% of 35? part whole STEP 2: Set up the proportion: (your percent is always over 100!) 35 is the total number of questions, or whole # of questions 80 = x 100 35 Cross multiply and solve for x. You got 28 questions right!
Test # 2 Yikes! You earned a 16% on a test out of 50 questions. How many questions did you get correct? What is 16% of 50? - this question could also look like this: 16% of 50 is what number? STEP 1: Identify the part and whole of the problem. What is 16% of 50? part whole STEP 2: Set up the proportion: (your percent is always over 100!) 16 = x 100 50 Cross multiply and solve for x. You got 8 questions right.
Remember: ‘of ‘ means whole! Whole is the denominator! Give it a try!Write these in your notebook! • Find 67% of 90 67 = x 100 90 Start by writing an empty proportion. Then, write your percent of 100. Now, decide whether 90 is the part or whole. 60.3
Another Example: • Find 145% of 210 145 = x 100 210 Do you have an empty proportion? Is your percent over 100? 304.5
Complete these problems in your notebook. The answers are on the screen after # 8. 3. Find 38% of 400 38 = x 100 400 4. Find 47% of 900
Keep Working! 5. 60% of 10 is what number? 60 = x 100 10 6. What number is 15% of 30? 15 = x 100 30
You are doing great! 7. 150% of 150 is what number? 8. What number is 59% of 20?
Answers! 3. 152 4. 423 5. 6 6. 4.5 7. 225 8. 11.8
Now you know how to find the percent of a number using proportions! • Now, complete 6-4 Practice B EVENS in your packet. • Before you continue with the rest of the program, show me your finished work.
Test # 1…AGAIN! What is 80% of 35? You know how to solve this using a proportion, but I know you equations, so let’s give it a whirl! Things to Remember: • I can solve any problem like this using a proportion or an equation. 2. Use these 3 word clues: of indicates whole is indicates part what number indicates x
Equation Method 3. Percent x Whole = Part What is 80% of 35? (.80) (35) = p Percent x Whole = Part = 28
Now you try it! 38% of what number is 400? Percent x Whole = Part ( ? ) ( ? ) = p Step 1: Enter percent as a decimal. ( .38 ) ( ? ) = p Step 2: Enter the Whole ( .38 ) ( 400 ) = p Step 3: Solve using Multiplication! = 152
Now you can find the percents of a number using equations! • With your partner, complete 6-4 Practice B # 13-16 using the Equation method!