# Can we go on! You have 5 minutes to complete check-up.

## Presentation on theme: "Can we go on! You have 5 minutes to complete check-up."— Presentation transcript:

Can we go on! You have 5 minutes to complete check-up.

Lets Check! 1.8 to 5 2.4 to 19 3.6 to 23 4.16 to 10 and 24 to 15 5.75meter/30sec. 2.5m/sec 6.\$8.75 per scarf 7.Danny 8.12 men

Writing and Solving Proportions I can write and solve proportions using ratios and algebra. Textbook Pages 412-416

Vocabulary Proportion: is an equation that shows that two ratios are equivalent. Ratio: 2 of 3 rowsRatio: 8 of 12 dots Proportion : 2/3 = 8/12

Cross Products Cross Product: when you multiply the numerator of each ratio by the denominator of the other ratio. The cross products of proportions are equal to each other. To see if two ratios form a proportion, check to see if the cross products are equal: 8 20 10 25 so multiply 25 time 8 and 10 time 20 What you get is 200=200

Try some Are these proportions: 10/16 = 5/8 Yes 3/8 = 15/40 Yes 3/5=12/18 No

Solving Using Mental Math: When one of the numbers in a proportion is unknown, you can find the number by solving the proportion. Just ask yourself what did they do to one to get the other. 4 = 20 12 x Multiply by 5 X= 60

Try some 1/5 = z/20 4 8/3 = k/18 48 9/c=3/12 36

Review Can someone remind me how we solve multiplication equations: We divide both sides by whatever number is with the variable. 3x = 18 Divide both sides by 3 X = 6

Solving using equations: You can solve proportions by using cross product and making an equation. You cross multiply then solve for the variable. 10 50 60 x Cross multiply. 10x = 3000 Solve by dividing both sides by 10 X=300

You try some! 91/x = 7/5 7x= 455 X=65 24/36 = 10/x 24x=360 X= 15 9/6 = h/14 6h=126 H=21

Practice Workbook Pages 105-106 odds

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