Name______Day & Block______
Solving Ratio Problems using Double Number Lines
- Watch the Learn Zillion video on double number lines: learnzillion.com - use quick code LZ591
- Solve these problems on your own paper. Remember that to get credit you MUST show how you can use double number lines to help you solve the problem -- even if you think the problem is so easy that you can figure out the answer in your head!
Remember these key things:
•label each number line with the information each line represents
•remember that for double number lines, the values shown on the number line must be in least to greatest order from left to right -- just like a regular number line!
•show the original ratio on the number line (this is usually at or near the beginning of the number line, but can sometimes be in other places)
•use tic marks (or vertical lines connecting the two number lines) to show where the numbers go
•make sure your equivalent ratios are lined up above and below each other
- At the zoo there are 3 lions for every 5 tigers. If there are 27 lions at the zoo, how many tigers are there?
- My recipe for lemonade uses 3 liters of water for the juice of 4 lemons (plus a lot of sugar, of course). If I am going to use 10 lemons to make lemonade, how much water should I use? (do not round when finding this answer)
- The fruit stand at the farmer’s market has 2 peaches for every 5 apples. If there are 130 apples on the fruit stand, how many peaches are there?
- Melissa gets paid $10 for every 2 hours she babysits. If she earned $75 babysitting last weekend, how many hours did she babysit? (Hint: If you are going to use a unit rate in solving this problem, the original ratio should not be written at the beginning of the number lines, since you’ll need to leave room for the unit rate to be to the left of the rate given. This is because the numbers on the number lines have to be in least to greatest order.)
- Mrs. Gibson baked a batch of 3 dozen cookies to feed the 40 students at the math club meeting. Next month she expects 60 students to attend. How many cookies should she bake? (Again, be careful about the placement of the original rate on your number lines. If you’re going to include a unit rate on your number lines, you need to leave room for that to be in the right spot.)
- I just love the banana pudding that the school cafeteria makes. They were nice enough to share the recipe with me, but the recipe makes a batch of pudding for hundreds of students, not a medium-sized family! Their recipe calls for 150 cups of vanilla pudding and 50 ripe bananas. If I only plan to use 3 ripe bananas, how many cups of pudding will I need? (Hint: this will be one of those times when the original ratio should not be written at the beginning of the number line - try putting it at the end.)
- Anna makes bead necklaces to sell at the craft fair. She advertises her necklaces at the price of $18 for 3 necklaces. If she sells all 20 of the necklaces she has made, how much money will she bring in? (Hint: be careful about where you place the original rate!)
- There were 250 7th graders and 200 8th graders who attended the middle school dance. They didn’t all get there at one time, but strangely, every time Dr. Nutting counted 7th graders and 8th graders, they were in the same ratio as the final attendance numbers! About 10 minutes after the dance started, the Dr. Nutting counted 100 7th graders there so far. How many 8th graders were there at that time? (Hint: be careful about where you place the original rate!)