Ask the Expert Challenging Word Problems Cassy Turner

Ask the Expert: Challenging Word Problems Cassy Turner

singaporemathsource. c om Cassy@singaporemathsource. com Slides at: bitly. com/sdehandouts Twitter Bio: Passionate about Singapore Math, Teacher Trainer/Coach, Treasure Hunter, Learner, Answer to the ultimate

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Polya’s Steps in Problem Solving 1. See 2. Plan 3. Do 4. Look Back

Part Whole Models Donna has 6 bananas. Mary has 8 bananas. They have ? bananas altogether. Donna Mary

Part-Whole models Donna has 6 bananas. Mary has 8 bananas. They have ? Bananas altogether. ? Donna Mary 6 8 They have 14 bananas altoget

Add challenge Donna has 46 bananas. Mary has 28 bananas. They have ? bananas altogether. ? Donna 46 Mary 28 They have 74 bananas altoget

Provide variation Donna has 52 bananas. The girls have 96 bananas altogether. How many bananas does Mary have? 96 Donna Mary 52 ? Mary has 44 bananas

Provide variation Mary has 44 bananas. The girls have 96 bananas altogether. How many bananas does Mary have? 96 Donna ? Mary 44 Donna has 52 banana

Part-Whole models …for multiplication and division introduce the concept of “equal parts/groups”.

Comparison Models There were 19 boys and 14 girls at the track meet. How many more boys than girls were at the track meet? 19 boys girls 14 ?

Comparison Models There were 19 boys at the track meet. There were 4 fewer girls than boys. How many girls were at the track meet? 19 boys girls ? 4

Multi-steps Provide Challenge James, Tom, and Cal collected a total of 48 baseball caps. James collected 31 caps. Tom collected 19 caps. How many caps did Cal collect ? 31 James Tom Cal 9 ? 48

Sam had 366 stamps in his stamp collection. He had 98 fewer stamps than Thomas. How many stamps do they have altogether? Step 1: How many stamps does Thomas have? 366 Step 2: How many stamps do they have altogether? 98 Sam Thomas ? 366 + 98 = 464 stamps Thomas has 464 stamps. ? 464 ? 366 Thomas Sam ? 464 + 366 = 830 The boys had 830 stamps altogether.

4. Ron had 5 times as much money as Tim. If Ron had $504 more than Tim, How much money did Ron and Tim have altogether?

1. Andy had some money in his wallet. After receiving $38 from his father and $189 from his mother, he went to town to buy a pair of rollerblades, which cost $98. Then he spent $24 on food and found that he had $182 left. How much money did Andy have in his wallet at first?

2. John had an equal number of pins and hats in the schools store. After selling 15 of the hats, the number of pins left was 4 times the number of remaining hats. How many pins and hats did he have in all at first?

5. 1 knife and 1 bowl cost $37. 2 such knives and 5 such bowls cost $89. Find the cost of 1 knife.

14. Josh saved 30% of his monthly salary and spent 20% of the remainder on food. If he had $280 left, how much was his monthly salary?

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3. Mr. Tan bought 6 magazines and 3 books for $63. A magazine cost $3 less than a book. Find the cost of each magazine.

8. A T-shirt cost $2 less than a pair of shorts. A dress shirt cost $13 more than the pair of shorts. Jill bought 5 of each item. If she paid $205 altogether, how much did each t-shirt cost?

11. The sum of four numbers is 203. 3. The 2 nd number is 9. 24 more than the 1 st number. The 3 rd number is 11. 05 more than the 2 nd number. The 4 th number is 21. 91 less than the 3 rd number. What is the greatest number?

15. 25% of a class of 32 pupils are boys. If some more boys join the class, the percentage of boys increases to 40%. How many boys join the class?

16. Rae bought 100 oranges and 46 apples. After she used an equal number of oranges and apples for making fruit juice. The ratio of her remaining oranges to apples became 5: 2. Find the total number of oranges and apples she used.

17. Robin ate some peanuts on Sunday. On Monday she ate 2 more peanuts than on Sunday. On Tuesday, Wednesday, Thursday, Friday, and Saturday she ate 2 more peanuts than the day before. By Saturday night she had eaten 77 peanuts in the whole week. How many peanuts did Robin eat on Wednesday?

The difference between two numbers is 2, 184. If the bigger number is 3 times the smaller number, find the sum of the two numbers.

The sides of a triangle are in the ratio 4: 5: 6. If the perimeter of the triangle is 60 cm, find the length of the shortest side. ? 60 cm 15 � 60 cm 1 � 60 cm ÷ 15 = 4 cm Shortest side 4 cm x 4 �=16 cm.