Question

Directions: Estimate the sum or difference of each problem. The first one is done for you.

Tip: Round the numbers to the nearest 10 before estimating the sum or difference.

1) 28 + 53=

First, look at the second digit in the number. If it is 5 or higher, round the first digit up. If it is 4 or lower, leave the first digit as it is.

28 = 30

53 = 50

30 + 50 = 80

2) 58 + 31=

3) 73 + 45=

4) 37 + 44=

5) 66 - 21=

6) 53 - 50=

7) 51 - 16=

8) 20 - 11=

9) 86 + 6=

10) 94 + 87=

Answer 1

that's inccorecct

Explanation

all 0

Answer 2

First, look at the second digit in each number. Since 8 is higher than 5, we round 28 up to 30. Since 3 is lower than 5, we leave 53 as it is.

1) 30 + 53 = 83

So, 28 + 53 is approximately 83 when rounded to the nearest 10.

2) 60 + 30 = 90

70 + 50 = 120

40 + 40 = 80

70 - 20 = 50

50 - 50 = 0

50 - 20 = 30

20 - 10 = 10

90 + 10 = 100

90 + 90 = 180