standard_description: Solve two-step word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding. (This standard is limited to problems posed with whole numbers and having whole number answers; students should know how to perform operations in the conventional order when there are no parentheses to specify a particular order (Order of Operations).)
problem_activity: Problem 1
Act 1: Watch the video
The Orange (Act-1)
.
a.   What do you notice? What do you wonder?
b.   How many linking cubes will it take to even out the balance scale? Make an estimate.
Problem 2
Act 2: Use the following information to determine how many cubes it will take until the balance is level with the orange -
[IMG]
[IMG]
Problem 3
Act 3: Watch
The Orange (Act-3)
. Was your answer reasonable? Why or why not?
Problem 4
Act 4 (the sequel):
a.   Jessica puts 28 grams of pinto beans and 36 grams of rice into a pot to make rice and beans. What is the total mass of the rice and beans?
b.   Lindsey bought 845 grams of potatoes at the grocery store. She uses some of them to make mashed potatoes. She now has 392 grams of potatoes left. How many grams of potatoes did Lindsey use to make the mashed potatoes?
c.   Jerry buys 6 bags of groceries. Each bag has a mass of 4 kilograms. What is the total mass, in kilograms, of Jerry’s grocery bags?


aligns: no