Rounding and estimating
Round 575 to the nearest 10
580
True or false?
135 - 112 = 112 - 135
false
Which equation is correct?
121 - 112 = ?
637 - 638 = ?
724 - 732 = ?
121 - 112 = ?
Solve this problem using the addition algorithm:
78 + 92 =
170
Jim collects rocks. He has 213 brown rocks and 189 gray rocks. How many rocks does he have all together?
402 rocks
Round 1,389 to the nearest 100.
1,400
True or false?
249 + 62 = 250 + 61
true
Write an equation to match this problem:
Sam is training to run a marathon. He ran 326 miles in January, 139 miles in February and 78 miles in March. How many miles has he run all together?
326 + 139 + 78 = ?
Solve this problem using the subtraction algorithm:
64 - 38 =
26
Billy is on a trip. His hotel is 250 miles away from his house. So far he has driven 126 miles. How far does he have left to drive?
124 miles
Round and add to find the estimate:
37 + 92 =
130
True or false?
78 - 53 = 70 - 45
true
Write an equation to match this story problem:
4th and 5th graders are having a contest to see who can read the most books. 4th grade has read 526 book and 5th grade has read 732 books. How many more books did 5th grade read than 4th?
732 - 526 = ? or
526 + ? = 732
Solve this problem using the addition algorithm:
398 + 525 =
923
Lilly and Jan are both reading the same book. Lilly has read 59 pages. Jan has read 134 pages. Who has read more pages? How many more?
Round and subtract to find the estimate:
344 - 127 =
210
Fill in the blank.
573 + 139 = _____ + 150
562
Write an equation to match this story problem:
Suzie's book is 940 pages long. She has read 821 pages so far. How many more pages does she have left to read?
940 - 821 = ? or
821 + ? = 940
Solve this problem using the subtraction algorithm:
940 - 387 =
553
North high school has 1,106 students and south high school has 3,853 students. How many students do they have all together?
4,959 students
Which of the following 2 numbers have a sum closest to 1,000?
280 730 540 620
280 and 730
Fill in the blank.
143 - 98 = _____ - 100
145
Write 1 or more equations to match this problem:
Bennett had 632 students. Over the summer, 43 students moved away and 57 new students moved in. How many students does Bennett have now?
632 - 43 + 57 = ? or
632 - 43 = ? and ? + 57 = ?
Solve this problem using the addition algorithm:
3,460 + 5,823 =
9,283
Jack is on a road trip. On day 1, he drives 45 miles from home. On day 2, he drives 49 more miles. On day 3 he realized he forgot something so he had to turn around and drive 75 miles back towards home. How far from home is he now?
19 miles