Problem of the Day: B) 400 C) 300 D) 100 1.8 Estimate Differences Problem of the Day: There were 418 tickets collected at the Lane Theater before noon. In the afternoon, there were 289 tickets collected. About how many tickets were collected in all? A) 700 B) 400 C) 300 D) 100

1.8 Estimate Differences Use compatible numbers (numbers that are easy to compute mentally and are close to the real numbers). 436 425 - 387 375 So, the group weighed about ____ pounds more than the yellow fish tuna. What other compatible numbers could you have used?

Try This! Estimate. Use compatible numbers. 1.8 Estimate Differences Try This! Estimate. Use compatible numbers. Estimate: 600 + 50 = ____ 73 75 - 22 ___ 376 - 148 - 150

Another Way: Use place value to round. 1.8 Estimate Differences Another Way: Use place value to round. 436 – 387 = Step 1: Round 436 to the nearest ten. 436 - 387

Another Way: Use place value to round. 1.8 Estimate Differences Another Way: Use place value to round. 436 – 387 = Step 2: Round 387 to the nearest ten. 436 440 - 387 - _______

Another Way: Use place value to round. 1.8 Estimate Differences Another Way: Use place value to round. 436 – 387 = Step 3: Find the difference of the rounded numbers. 436 440 - 387 390 So, 436 – 387 is about _____.

Try This! Estimate. Use place value to round. 1.8 Estimate Differences Try This! Estimate. Use place value to round. 761 800 - 528 ___ 642 - 287 - 300

1.8 Estimate Differences Use compatible numbers to complete the problem. Then estimate the difference. 546 550 - 209 -___ Share & Show

1.8 Estimate Differences 2) Use rounding or compatible numbers to estimate the difference. 57 - 21 -___ Share & Show

1.8 Estimate Differences 3) Use rounding or compatible numbers to estimate the difference. 642 - 137 -___ Share & Show

1.8 Estimate Differences 4) Use rounding or compatible numbers to estimate the difference. 374 - 252 -___ Share & Show