brain archive

Problem

Imagine you start your lemonade stand with 1,959 cups of lemonade. You sell 42 cups of lemonade, but then 7 cups are returned to you because they have bugs in them. Ew! How many cups of lemonade do you end up with (including the buggy ones that are returned to you)?

Answer

Math Strategies Used: Make an organized list and Write an equation

You start with 1,959 cups.
You sell 42 cups.
You get back 7 cups.

So 1,959 – 42 + 7 = 1,924 cups of lemonade.

That's a lot of lemonade!

Problem

How many friends helped Evan sell lemonade during the Lemonade War?

(Ooh, this problem is tricky. You have to read the book to answer it!)

Answer

Math Strategies Used: Make an organized list and Write an equation

Here are the friends who helped Evan:

Scott Spencer
Paul
Jack
Ryan

So 1 + 1 + 1 + 1 = 4! Four friends helped Evan sell lemonade during the Lemonade War.

Problem

Evan and Scott decide to sell lemonade every day for a whole week (except for Monday). Every day, except for Monday, they sell 45 cups of lemonade. They charge 50¢ for each cup. How much money do they have at the end of the week? If they split the money evenly, how much money does each one make?

Answer

Math Strategies Used: Make an organized list and Write an equation

On Sunday, they sell 45 cups
On Monday, they sell 0 cups
On Tuesday, they sell 45 cups
On Wednesday, they sell 45 cups
On Thursday, they sell 45 cups
On Friday, they sell 45 cups
On Saturday, they sell 45 cups

So all together, Evan and Scott sell 270 cups of lemonade.
(45 + 45 + 45 + 45 + 45 + 45 = 270)

They sell each cup of lemonade for 50¢, so every time they sell 2 cups they make a dollar. How many groups of 2 are there in 270?

270 ÷ 2 = 135

So Scott and Evan earn $135 by the end of the week.

They split their earnings evenly: Evan gets half and Scott gets half. How much is half of $135?

$135 ÷ 2 = $67.50

Evan and Scott each get $67.50 at the end of the week. Wow! That's a lot of lemon loot!

Problem

If Evan makes $110.10 selling lemonade, and Jessie makes $60.49 selling lemonade, how much more money will Evan make?

Answer

Math Strategies Used: Write an equation

110.10 – 60.49 cents = 49.61

Evan will make $49.61 more selling lemonade than Jessie does.

Problem

If Jessie starts out with $50, and then she sells 60 cups of lemonade at 50¢ each, how much money will she have all together?

Answer

Math Strategies Used: Write an equation

60 cups x 50 cents = 3000 cents, which equals $30

So, Jessie will have $30 after she sells the lemonade. Now, add that money to the $50 she already had:

$30 + $50 = $80

Jessie will have $80 all together.

Problem

If Jessie and Megan earn $30 selling lemonade each day for three days in a row, and Megan has an extra $10 to add to their earnings, will they have enough money to win the Lemonade War?

Answer

Math Strategies Used:Make an organized list and Write an equation

Day 1 they earn $30

Day 2 they earn $30

Day 3 they earn $30

Megan has an extra $10

So...$30 + $30 + $30 + $10 = $100.

Jessie and Megan will have $100, which is enough to win the Lemonade War. (Remember, Evan had just $62.11 at the end of the five days.)

Problem

If Evan has 60 cups of lemonade and he sells each cup for $1.50, how much money will he make if he sells all of the lemonade?

Answer

Math Strategies Used: Write an equation

60 cups x $1.50 = $90.

Evan will make $90 if he sells all of the lemonade.

Problem

If Evan had 8 pitchers of lemonade and each pitcher gives out 8 cups, how much money will he make if he sells each cup for 50 cents?

Answer

Math Strategies Used: Solve a simpler problem and Write an equation

1. How many cups of lemonade does Evan have?

Evan has 8 (pitchers) x 8 (cups) = 64 cups of lemonade.

2. How much money will he make?

64 cups x $0.50 = $32.

Evan will make $32 if he sells all of the lemonade.

Problem

Evan is organizing a basketball tournament on the school playground. He needs to put five kids on each team. Twenty-two kids show up to play. How many teams can he organize? Are there any kids leftover? If so, how many?

Answer

Math Strategies Used: Draw a picture and Write an equation

Draw 22 X's on the page. Group the X's in rows of 5.

X X X X X = 5 kids = 1 team

X X X X X = 5 kids = 1 team

X X X X X = 5 kids = 1 team

X X X X X = 5 kids = 1 team

X X = two kids leftover

Evan can organize 4 teams with 2 kids leftover.

22 ÷ 5 = 4, remainder 2

Problem

Jessie has $3.67 in her lockbox, all in coins. She has twice as many quarters as she has dimes. She has the same number of nickels as she has dollar bills. She has one more penny than she has dimes. How many dollar bills, quarters, dimes, nickels, and pennies does Jessie have?

Answer

Math Strategies Used: Make an organized list and Guess and check

Okay, first, we know that Jessie has no dollar bills because the problem tells us that the money is all in coins. That means she has no nickels either.

Dollar bills 0
Quarters
Dimes
Nickels 0
Pennies

Now, let's make a guess. Let's guess that she has eight quarters. That would mean she has four dimes. How much money does that equal? Eight quarters equals two dollars and four dimes equals forty cents. Hmm. That's only $2.40. Not enough money. Let's guess again.

Let's guess she has twelve quarters. That would mean she has six dimes. How much money does that equal? Twelve quarters equals three dollars and six dimes equals sixty cents. Hey! That's $3.60, which is just seven cents less than the total amount of $3.67. If Jessie has seven pennies, that's one more penny than she has dimes (6 dimes). So we can fill in the rest of our list and then check our answer again:

____________________________

TOTAL = $3.67

Good job!