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Adding/Subtracting!
Multiplying/Dividing!
Comparing/Reciprocals
Word Problems!
Word Problems!
100
10 2/5 + 3 1/2 =
13 9/10. Remember to stack your numbers, find your common denominator, and add!
100
3/8 x 4/9=
1/6. To multiply we SLIDE! Remember, cross cancelling will make it easier!
100
What is the reciprocal of 3/4
What is 4/3. Remember, a reciprocal is a "flipped" fraction. By definition, a reciprocal is a pair of fractions that can be multiplied to get 1. We use a reciprocal when we are dividing fractions---we remember to use the reciprocal by saying "Keep the first fraction, change the sign to multiplication, and FLIP."
100
Ms. Boling is making 5 batches of muffins for a teachers' breakfast. If each batch calls for 1 2/3 cup sugar, how much sugar will she need?
8 1/3 cups. You should have multiplied 5 x 1 2/3 or you could have added 1 2/3 + 1 2/3 + 1 2/3 +1 2/3 +1 2/3. In fact, that should have been a great clue! Anytime you can do repeated addition to solve, you can also multiply. Also knowing she needs 1 2/3 cup for EACH batch gives us another hint to multiply.
100
Alex is committed to practicing his guitar for 4 1/3 hours each week. If he practices for 1/3 hour each time, how many times a week does he practice? BONUS: How many minutes is 1/3 of an hour. How many minutes did Alex practice? (give yourself an extra 100 points if you get this!)
13. Divide. You are looking for how many 1/3 hour blocks it takes to make 4 1/3 hours (or saying 1/3 would "fit in" to 4 1/3 hours how many times). When you divide you must make your mixed number improper, and you must KEEP CHANGE FLIP. You may have also gotten your answer by knowing that dividing my 1/3 is the same as multiplying by 3. 4x3= 12 1/3 x 3= 1 12 + 1 = 13 Bonus. 1/3 OF 60 minutes (multiply) = 20 minutes. Alex practices 260 minutes. 4 hours = 60 x 4 (240). 1/3 hour = 20 minutes. 240 + 20 = 260
200
8 2/5 - 2 2/3=
5 11/15. First stack your numbers. Find your common denominator. You can't do 6/15 - 10/15 without borrowing! If you borrow 1 from the 8, it becomes 7. Name the one you borrowed 15/15. Add it to the 6/15. Now you have 21/15 and can subtract.
200
6 ÷ 1 1/3
4 1/2. Remember to put the whole number over 1, and convert 1 1/3 to an improper fraction, then to multiply just SLIDE! Remember, cross cancelling makes life easy. :)
200
What is the reciprocal of 8?
1/8. 8 written as a fraction is 8/1. A reciprocal is a "flipped" fraction. By definition a reciprocal is two fractions that equal 1 when multiplied. 1/8 x 8/1 =1
200
Jan needs to run 9/10 of a mile. She ran 3/10 of a mile and rested. Then she ran 1/10 of a mile more. How much more of a mile must Jan run?
5/10 or 1/2. First add what you know she has already completed 3/10 + 1/10 = 4/10. Now, to find out how much is LEFT, subtract. 9/10- 4/10 = 5/10 or 1/2.
200
A small bag of carrots weighs 8 1/2 ounces. If the average carrot weighs 1/4 ounce, how many carrots are in the bag?
34. You need to divide. The clue is, you are seeing how many times 1/4 will go into 8 1/2 ounces. 8 1/2 divided by 1/4 = 34. Remember, you must make the mixed number improper (use the "backwards C" to remind you!) and don't forget to KEEP CHANGE FLIP! You can check yourself by doing the inverse operation 1/4 x 34= 8 1/2.
300
8 - 3 3/4
4 1/4. Stack your numbers. You can't just drop the 3/4 down or you haven't subtracted it! Borrow from the 8 and make it a 7. Name the 1 you borrowed 4/4.
300
3/4 ÷ 4 =
3/16. Put the whole number over 1, then KEEP, CHANGE, FLIP!
300
Which is bigger 4/5 or 3/7?
4/5. There are several ways you could know this. *get a common denominator--then you can compare the fractions directly. In this case, 4/5 = 28/35 3/7= 15/35 I know that 28/35 is more than 15/35. You could also cross multiply (just a shortcut to the above)
300
Mr. Sagona has a brown rat that is 4 3/4 inches long. He has a gray rat that is 3 1/2 inches long. How much longer is the brown rat?
1 1/4 inches. You need to subtract. The key phrase here is "How much longer.." Remember, when we make comparisons like this we are looking for a DIFFERENCE. The answer to a subtraction problem is called the difference! Stack your numbers, find a common denominator, and subtract!
300
3/5 of Mrs. Keyer's 40 7th graders are going to festival! How many students are going to festival?
24. You need to multiply. The clue is that you are asking, "What is 3/5 OF 40?" In this context, OF means MULTIPLY! To multiply, put the 40 over a 1 and S-L-I-D-E! Wheeeee!!!
400
2 2/3 + 1 1/4=
3 11/12. Stack your numbers. Find a common denominator! Add!
400
1 2/5 x 1 5/7
2 2/5. Remember to convert your mixed numbers into improper fractions (think backwards C), then just slide! Remember, cross cancelling makes it easier!
400
Ms. Jones needs 3/8 cup of sugar to bake bread. She has 3/5 cup. Does she have enough?
Yes. In order to answer, you need to ask is 3/5 > 3/8? You can either get a common denominator or cross-multiply. 3/5 = 24/40 3/8= 15/40 so since she has 3/5 cup and only needs 3/8 of a cup so Ms. Jones WILL bake bread!
400
Mrs. Lee's family plans to take a long trip over the holidays, but with a baby in the car, they need to stop often. If they drive 1/3 of the trip on the first day, and 2/5 on the second day, how far will they have gone?
11/15 of the trip. You need to add. Even though the problem doesn't say a key phrase like "in all" or "together," it is implied. We're just putting the two amounts together. To add, stack your numbers then find a common denominator.
400
Jeff had 8 1/2 feet of rope to use for a Boy Scout project. He gave a friend 3 3/4 feet of rope. How much rope does Jeff have left?
4 3/4. You need to subtract. The key phrase is "How much is left?" If you did not get the correct answer, make sure you borrowed!! 1/2 = 2/4 and you can't do 2/4 - 3/4 without regrouping!
500
A frog hops 3 1/2 inches, and then 2 1/4 inches. How far has it hopped altogether?
5 3/4 inches. Stack the numbers. Find common denominator. Add!
500
4 2/3 ÷ 1 1/2 =
3 1/9. Don't forget to convert your mixed numbers to improper fractions, and because we're dividing KEEP CHANGE FLIP!!!!
500
Which is larger 3/5 or 2/3?
2/3. You can get your answer in several ways. If you get a common denominator, 3/5 = 9/15 and 2/3 = 10/15. Now that you have a common denominator, you can compare the fractions directly. You can also cross multiply.
500
Alma sold 55 boxes of Girl Scout cookies. If 3/5 of the cookies she sold were Thin Mints, how many boxes of Thin Mints did she sell?
33. You are asking, "What is 3/5 OF 55!" In this context, OF means MULTIPLY! Put the 55 over 1. Cross cancel to make the problem easier, and voila!
500
A bookshelf is 16 1/2 inches wide. If math workbooks are 3/4 inches thick, how many can fit on a shelf?
22. You need to divide. The clue is, you are seeing how many 3/4 inch books will fit into a 16 1/2 inch shelf or how many times 3/4 will "go into" 16 1/2. Remember, order matters in division.. you must make the mixed number improper, and you must KEEP CHANGE FLIP. You can check yourself by asking does 22 x 3/4 = 16 1/2? It does!