Question

1. decompose one number to help find the difference. (lesson 2 - 7) 367 - 228 = 15. gabe is trying to solve 246 + 367. which equation shows how he could adjust the addends to find the sum? (lesson 2 - 8) a. 250 + 360 =? b. 250 + 370 =? c. 250 + 363 =? d. 250 + 371 =? 16. use the bar diagram to help you find the missing number. (lesson 2 - 9) 219 + __ = 450 450 - __ = 219 17. do you think it makes more sense to decompose both addends or adjust both addends to solve 388 + 472? explain. (lesson 2 - 10) 18. which of the following equations can you use to solve this subtraction equation? (lesson 2 - 11) 836 - 377 =? a. 377 + 459 = 836 b. 459 - 377 = 836 c. 459 - 836 = 377 d. 836 + 459 = 377 19. enrique read 249 pages of his book in june and 227 pages of his book in july. the book has a total of 638 pages and enrique wants to know how many pages he has left to read. (lesson 2 - 12) which set of equations could be used to solve the problem? a. 227 + 249 = 476 638 - 227 = 411 b. 249 + 227 = 476 638 - 476 = 162 c. 638 - 249 = 389 389 + 227 = 616 d. 638 - 227 = 411 411 + 249 = 660

Explanation:

14.

Step1: Decompose numbers

Decompose 367 as 300 + 60+7 and 228 as 200 + 20+8.
367 - 228=(300 - 200)+(60 - 20)+(7 - 8)=100 + 40+( - 1)=139

Step1: Adjust addends

246 is close to 250 (add 4) and 367 is close to 360 (subtract 7). To keep the sum the same, when we add 4 to 246 and subtract 7 from 367, the new equation is 250+360.

Step1: Use subtraction for first blank

To find the missing number in 219+? = 450, we use 450 - 219.

Step2: Use subtraction for second blank

For 450 -?=219, the missing number is also 450 - 219 = 231

Answer:

139

15.