The app, "MADS 24" is a great app for practicing the intermediate version of 24. 
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Kindergarten: Different ways to represent numbers
1st  Grade: Modeling 2 digit numbers with base ten blocks
2nd Grade: Doubles Plus 2 for Addition
3rd Grade: Compensation Strategy for Subtraction
4th Grade: Building Down when Multiplying by 9
5th Grade: Mental Math Division Strategies

Next week will be the first week I draw a winner for the Weekly 24 Challenge. I am excited and hope a lot of kids will participate!

Wish List: We use skinny dry erase markers in the lab constantly and are running low.

For Primary Cards: Choose the side that you can use the numbers to equal the number in the middle.
For Intermediate Cards: Make 24 using all 4 numbers once and only once.

Turn in your answers for a chance to win a weekly prize

1)  A motorist made a 60-mile trip averaging 20 miles per hour. On the return trip, he averaged 30 miles per hour. What was the motorist's average speed for the entire trip?

2)  100 pounds of chocolate is packaged into boxes each containing 1 1/4 pounds of chocolate. Each box is then sold for $1.75. What is the total selling price for all of the boxes of chocolate?
3)  In the multiplication problem below, A and B stand for different digits. Find A and B.

              A  B
        x    B  A
          1  1  4

      3  0  4       
      3  1  5  4





Solutions:
1)  The average speed for any trip is the total distance divided by the total time spent in traveling. The total distance was 120 miles and the total time was 5 hours. The average speed equals (120 miles)/(5 hours) or 24 miles/hour or 24 mph.
2)  We need to know the number of boxes that were packaged in order to find the total selling price. The number of boxes is obtained by dividing 100 by 1 1/4: 100 divided by 5/4 = 100 x 4/5 = 80.
3)  The first partial product 114 is equal to the product of AB and A. The second partial product 304 is equal to the product of AB and B. Then A must be less than B.
     Method 1: Since the product of AB and A is 114, A is a divisor of 114. Therefore A may be 2, 3, or 6. Since AB x A = 114, A cannot be 2 because AB x A would then be less 60. Similarly, A 
     cannot be 6 since AB x A would then be greater than 360. Therefore A must be 3 and AB must be 114/3 or 38. Thus A = 3 and B = 8. 
     Method 2: From the first partial product, observe that B x A must end in 4. Since A is less than B, A = 2 and B = 7, or A = 3 and B = 8, or A = 4 and B = 6. But 27 x 2 = 54, 46 x 4 = 184, and 38 x 3 = 114. Only the third equation satisfies the given conditions. So A = 3 and B = 8. 
     Method 3: From the second partial product 304, we see that B x B ends in 4. Then B = 2 or 8. If B =2, then A must be 1 because A is less than B. But 12 x 21 = 252. If B = 8 and AB x B = 304, then AB = 304/8 or 38 and 38 x 83 = 3154. Therefore A = 3 and B = 8. 

it.

Primary:
1 Dot: Can you make 4 using 7 and 11 or 6 and 11? How?
2 Dots: Can you make 3 using 8/11/7 or 2/12/7? How?
3 Dots: Can you make 24 using 8/9/21 or 17/14/7? How?

Intermediate:
1 Dot: How can you make 24 using 2, 4, 8, and 4?
2 Dots: How can you make 24 using 1, 9, 4, and 7?
3 Dots: How can you make 24 using 2, 3, 5, and 3?

​1)  Five brothers, each born in a different year, share a gift of $100 according to the following arrangement: each boy, except the youngest, gets $5 more than his next younger brother. How much does the youngest boy get?
2)  When I open my math book, two pages face me and the sum of the two page numbers is 317. What is the number of the very next page? 
3)  6, 14, and 15 are factors of the natural numbers N. What is the smallest value that N can have?
Solutions:
1) Method 1: The average amount received by the 5 boys is $20. In order of age, the third boy receives the average amount of $20. The youngest receives $10 less than the third boy. Therefore, the youngest receives $10.
   Method 2: Let Y represent the amount received by the youngest boy. Then the amounts received are Y, Y + 5, Y + 10, Y + 15, and Y + 20. These amounts can be regrouped and totaled as Y + Y + Y +Y + Y + 5 + 10 + 15 + 20, or more simply as 5Y + 50. Then, 5Y + 50 = 100, 5Y = 50, and Y = 10. The youngest receives $10.
2) The average of the two consecutive page numbers is 317/2 = 158.5. Then the page numbers are 158 and 159, with 159 being the number of the right-hand page. The next page number is 160.
3) Method 1: The LCM of a set of numbers is the smallest number N which each number of the set will divide exactly. LMC(6,14,15) = 210.
    Method 2: List the prime factors of each of the given factors of N: 6 = 2 x 3; 14 = 2 x 7, 15 = 3 x 5. N must have 2, 3, 5, and 7 as factors. Then N = 2 x 3 x 5 x 7 = 210.