Mrs. Christine Sce

Welcome back to school!  I hope you all had a wonderful winter break!  Let's get excited about solving math problems in the new year!  Hope to read your posts soon!

6 ducks swim. 5 ducks sink. How many ducks still swim?

2 kids are raking leaves. Each child has to rake 3 piles of leaves. How many piles of leaves will they have in all?

3 people go on a picnic. Each one uses 2 napkins and eats 3 cookies. How many napkins are used in all? How many cookies were eaten in all?

We have 24 students divided into 6 equal groups. They are sitting at tables painting. Each table has one yellow paint jar, twice as many red jars, and twice as many blue jars as red ones. How many students are in each group? How many blue jars are on each table? How many red jars in all? How many paint jars in all?

Sara is bored playing with blocks while babysitting her baby brother. To keep herself busy, she decides to stack up all the blocks so that each row has one less block than the row below. There are a total of 55 blocks, and Sara wants to end up with just one block on top. How many should she put in the bottom row?

Zach received money for his birthday. That night he went to dinner with his friend. He spent half of his money for dinner. Then he tipped the waiter $6.00. The next evening he bought candy, spent half of the money he had left, and tipped the cashier $2.00. The next night he went to dinner again, spent half of the money he had left and tipped the waiter $1.00. At this time he had $6.00 left. How much money did he start with?

There were a number of bats in a cave.  Two bats could see out of the right eye, three could see out of the left eye, four could not see out of the left eye, and five could not see out of the right eye.  What is the least number of bats in the cave and what might their eyesight have been?  (Hint:  Were they totally blind, blind only in the right eye, etc...?) The least number of bats in the cave is seven. Here are 3 possible solutions: (1) 2 see out of both eyes, 1 sees out of only the left eye, 4 are blind (2) 3 see out of the left eye only, 2 see out of only the right eye, 2 are blind (3) 1 sees out of both eyes, 2 sees out of only the left, 1 sees out of only the right, 3 are blind

Mr. Green pays a painter $504 to paint his house.  Mr. Green buys the paint, which costs $168.  If the painter works 42 hours on the house, how much does he earn per hour? The painter earns $12 per hour. $504 / 42 = $12 The hard part of this problem was deciding which information was not necessary to calculate the answer!

Sue had the best average.  She hit 75 out of 100 pitches for an average of 75%.  Derek hit 75 out of 100 pitches in his 1st round and then 35 out of 50 for his 2nd round.  Add his hits in both rounds for a total of 110 hits out of 150 pitches, which is an average of 73.3%

All of you got the right answer, but you did not calculate Derek's average correctly.  You cannot simply add the fractions together and divide by 2 to get 72.5% because the fractions are not equally weighted.  Derek's first round average was 75% (75/100) and his second round average was 70% (35/50).  Two thirds of his hits were at a 75% average and 1/3 of his hits were at a 70% average.  2/3 * (75%) + 1/3 * (70%) = 73.3%