Addition, Subtraction, and Rounding
A library has 1,200 books. They receive a donation of 450 books, but 200 books are old and need to be removed. How many books are in the library now?
A classroom has 18 desks. The teacher buys 6 more desks, and each desk has 4 legs. How many desk legs are there in total?
1. Add: 18+6=24 desks.
2. Multiply: 24×4=96 legs
20 x 4 = 80
4 x 4 = 16
80+16= 96
Write the area and perimeter formula.
Area: length x width
Perimeter: (Length x 2) + (Width x 2)
Mia's soccer practice started at 3:15 p.m. and ended at 4:10 p.m.. How long was Mia's soccer practice?
45 minutes until 4:00 p.m.
10 minutes until 4:10 p.m.
45+10 = 55
Fill in the blank:
The number above the fraction line is the __________
The number below the fraction line is the __________
The fraction line could also represent ____________
1. Numerator
2. Denominator
3. Division
A bakery sold 847 cupcakes on Monday and 564 cupcakes on Tuesday. Estimate how many cupcakes the bakery made on both days, using compatible numbers.
Round 847 to a compatible number near 850 (since 850 is easy to work with).
Round 564 to a compatible number near 550 (since 550 is also easy to work with).
850 + 550=1,400 total amount of cupcakes.
Amara has 84 marbles. She distributes the same number of marbles onto 7 trays. Then, Amara's friend adds 4 more marbles to each tray. How many marbles are on each tray now?
1. 84 divided by 7 to find out how many marbles per tray. 84÷7 = 12
2. add 4 more marbles to each tray:
12 + 4 = 16
Steven has a rectangular rug with a perimeter of 16 feet. The width of the rug is 5 feet. What is the length of the rug?
5 + 5 = 10
16 - 10 = 6
6 divided by 2 = 3
The length of the rug is 3 feet.
Jared has a canister that has 48 ounces of homemade trail mix. He wants to package the mix in bags that each hold 16 ounces of mix. How many bags can Jared fill?
Show me your equation with an unknown.
Jared can fill 3 bags.
There is a walking trail at the park. Four laps around the trail is a distance of 1 mile. How many laps does it take to walk 3/4 mile?
3 Laps
Charlie has 52 stamps. He puts 25 stamps on envelopes to mail. How many stamps does he have left? Use a number line to represent and solve
52-25 = 27
Number line should start at 25 (or 0) and take 27 hops until it got to 52.
A bakery bakes 18 loaves of bread in the morning and 24 loaves in the afternoon. In the evening, they bake 18 more loaves. If they package the loaves into boxes of 6, how many boxes will they need?
1. Add: 18 + 24 = 42 loaves of bread
2. Add: 42 + 18 = 60
4. Multiply: 6 x y = 60
y = 10
So, they can package the loaves in 10 boxes.
David has a rectangular bedroom with a rectangular closet. Draw a line to break apart the figure into rectangles, then tell me the total area of David's room.
Total area is 46 sq feet.
Marvel’s Delivery Service delivered three packages to Ms. Wilson. The packages have masses of 9 kilograms, 12 kilograms, and 5 kilograms. What is the total mass of the three packages? Use the bar model to help you solve.
A bar model should have 9kg, 12kg and 5 kg at the top with a total of 26 kg at the bottom.
Alexa and Rose read books that have the same number of pages. Alexa's book is divided into 8 equal chapters. Rose's book is divided into 6 equal chapters. Both girls read 3 chapters of their book.
Write a fraction to describe wha tpart of the book each girl read. Then tell me who read more pages
Alexa read 3/8 and Rose read 3/6.
Rose read more because if our numerators are the same, then we look at the denominator. If the denominator is smaller, then our pieces are larger!
A total of 907 people went to a fishing tournament. Of these people, 626 arrived before noon. Alina estimates that fewer than 300 people arrived in the afternoon. How did she estimate? Explain.
Alina rounded to the nearest hundred.
She rounded 907 to 900. Then, she rounded 626 to 600. Then, she subtracted 900-600= 300.
Rory has a 21-inch-long ribbon. He divides the ribbon into 3 equal parts. Then, he trims one of the pieces, leaving it 3 inches long. How much ribbon did Rory cut from that piece?
1. Find the length of each piece after separating into 3 pieces:
21÷3=7
2. Determine how much was cut:
7 - 3 = 4
So, 4 inches were cut from the piece of ribbon.
Elizabeth built a sandbox that is 4 feet long and 4 feet wide. She also built a flower garden that is 4 feet long and 6 feet wide and a vegetable garden that is 4 feet long and 8 feet wide. How much do the areas change from the sandbox to the flower garden to the vegetable garden?
The area of the sandbox is 16 square feet because 4 x 4 - 16.
The flower garden is 24 square feet because 4 x 6 = 24.
The vegetable garden is 32 square feet because 4 x 8 = 32
The areas increase each time by 8 square feet.
Haley and Richelle baked 2 cakes. They cut both cakes into 8 equal slices. Each slice weighs about 2 ounces. Which is the combined weight of the cakes?
Combined weight is 32 ounces.
Write 3 equivalent fractions to 3/4.
6/8, 9/12, 12/16
What is the difference of 650 - 318?
Part A:
Write an equation that shows the most reasonable estimate of difference.
Part B:
What is the exact difference?
The most reasonable esimate would be to round to the nearest tens.
660-320 = 340
The exact difference is 341.
A photographer is taking a picture of the 41 members of the school band. There are 5 rows with 7 members in each row. How many members are not in rows?
Use a bar model to show (hint you will have 2 bar models, one with division/multiplication, and one with addition/subtraction)
The bar model should be:
1. A bar model with 5 blocks, 7 in each block
5 x 7 = 35
2.The second bar model should have 35 people in a block, and an empty block. The total number should be written as 41.
After solving, the extra block should be 6.
Find the unknown side lengths of the shape. Write your equations with an unknown.
18 + N = 25
25-18= N
N = 7
At the space center, Katrina bough a model of a shuttle. She started working on the model the next day at 11:13 a.m. She worked until leaving for lunch at 11:51 a.m. After lunch, she worked on the model again from 1:29 p.m. until 1:48 p.m. How long did Katrina work on the model?
57 Minutes
There are 4 1/8th parts in 1/4th so I need to do 3 times as many. So there are 12 1/8th parts.