addition with regrouping
128
+ 324
-----------
452
423
- 213
-----------
210
54
50
141
100
A shop sells 675 posters. It sells 325 calendars. Round each number to the nearest 100 to estimate about how many posters and calendars the store sold in all.
700 + 300 = about 1,000 posters and calendars
424
+ 567
-----------
991
675
- 489
----------
186
141
140
321
300
Andrea buys 760 bricks. He buys 575 red bricks and 137 tan bricks. The rest of the bricks are grey. Write and solve an equation to find how many grey bricks Andrea buys.
Hint: multi-step problem. What do you need to solve first?
1. 575 + 137= 712
2. 760 - 712 = 48 grey bricks
1,034
+ 946
------------
1,980
978
- 569
-----------
409
385
390
889
900
Darian sells 1,237 bags of popcorn and 421 bags of peanuts. How many bags of popcorn and peanuts does Darian sell in all?
1,237 + 421 = 1,658
2,867
+ 3,467
------------
6,334
- 1,584
-------------
1,059
1,467
1,470
975
1,000
A zoo has 309 reptiles. There are 83 lizards and 62 turtles. The rest are snakes. How many snakes are at the zoo?
Hint: multi-step problem. 309 reptiles is the total.
1. 83 + 62 = 145
2. 309 - 145 = 164 snakes
12,456
+ 24,786
---------------
37,242
34,578
- 15,899
---------------
18,679
56,893
56,890
34,821
34,800
Liz earns 321 points in the first round of a math contest. She earns another 378 points in the second round and 215 points in the third round. Liz says she has earned 804 points total. Is Liz's answer reasonable?
Hint: start with rounding, then add or subtract to see if 804 is a reasonable answer.
round 321, 378, and 215.
300 + 400 + 200=900
804 is NOT reasonable