Unit 2 Review

Estimates

100

Estimate 52 + 39 

50 + 40 = 90

200

Use an estimate to find about how much 504 - 195 is 

500 - 200 = 300

300

Last week, 4th graders spent 2,095 minutes on YouTube and 3,902 minutes on TikTok. Estimate about how many more minutes they spent on TikTok. 

Either 3,900 - 2,100 = 1,800 minutes

OR 4,000 - 2,000 = 2,000 minutes

400

Estimate the sum for 4,796 + 3,210

4,800 + 3,200 = 8,000

OR 5,000 + 3,000 = 8,000

500

The tallest mountain in New Hampshire is Mount Washington at 6,288 feet tall. The tallest mountain in the USA is Alaska's Denali at 20,310 feet. Use estimates to find out about how much taller Denali is than Mount Washington. 

20,300 - 6,300 = 14,000

OR 20,000 - 6,000 = 14,000

Grab Bag

100

What is the definition of the word "sum"

The answer to an addition problem

200

If you need to find the "difference" between two numbers, what operation should you use? 

Subtraction

300

What is the missing digit?

    8 _ 9 

+  3 5 4
 1,2 1 3

5 because...

         859

    +   354
      1,213

      

400

Use compensation to find 1,995 + 286

(1,995 + 5) + (286-5) 

2,000 + 281 = 2,281

500

What is the missing digit

  8,84__

- 7,528

  1,315

3 because ...

   8,843
-  7,528
   1,315

Addition

100

Find the sum of 5,328 + 4,281

9,609

200

What is 60,598 + 32,975

93,573

300

The bodega sold 12,578 pastelitos last year. They sold 8,984 pastelitos the year before that. How many pastelitos did they sell in all? 

  12,578 +
+ 8,984 
 21,562

400

Fill in the missing digit

     56,_92
+   27,473
      84,265

7 because...

    56,792
+  27,473
    84,265

500

The Arlington school spent $495 on pencils, $1,589 on whiteboard markers, and $505 on tissues this year. How much did Arlington School spend in total? 

495 + 505 + 1,589 = 1,000 + 1,589 = $2,589

Subtraction

100

Find the difference between 131 and 59?

131 - 59 = 72

200

Solve

  45,584
- 19,258

  45,584
- 19,258
  26,326

300

A new Tesla costs $46,459. A new Toyota costs $28,189. How much more does the Tesla cost? 

    46,459
-   28,189
  $18,270

400

What is the missing digit

   56,_95
-  18,374
   37,921

2 because 

   56,295
-  18,374
   37,921

500

Arlington students voted for their favorite lunch. 

359 students chose pizza
139 students chose cheeseburgers
41 students chose chicken nuggets. 

How many more students chose pizza than cheeseburgers and chicken nuggets combined?

359 - (139 + 41) 

    359
-   180
    179 more students