Question

3.1 daily practice day 11

1. can you solve this riddle about a number?

• the number is between the two hundreds, 300 and 400.
• you will round down to the nearest hundred.

circle the correct answer.
296 378 344 406

1. wallys house is 123 minutes from his work. lorettas house is 19 minutes from work. how much further is wallys house than lorettas from work? use the number line to solve this problem.

1. which two numbers when rounded to the nearest hundred both round to 600?

655 and 631
562 and 649
610 and 545
527 and 588

1. use base - ten notation to solve. 742 - 266

Explanation:

Step1: Analyze number - range and rounding for question 1

The number is between 300 and 400 and rounds down to the nearest hundred. A number rounds down if its tens digit is less than 5. Among 296 (not in range), 378 (rounds up), 344 (rounds down), 406 (not in range), the answer is 344.

Step2: Calculate distance - difference for question 2

To find how much further Wally's house is, subtract Loretta's time from Wally's. $123−19 = 104$ minutes.

Step3: Check rounding for question 3

For 655 rounds to 700, 631 rounds to 600; 562 rounds to 600, 649 rounds to 600; 610 rounds to 600, 545 rounds to 500; 527 rounds to 500, 588 rounds to 600. The pair is 562 and 649.

Step4: Perform subtraction in base - ten for question 4

$742=7\times100 + 4\times10+2$ and $266 = 2\times100+6\times10 + 6$.
$742-266=(700 + 40+2)-(200 + 60+6)$
$=(700-200)+(40 - 60)+(2 - 6)$
$=500-20 - 4=476$

Answer:

1. 344
2. 104 minutes
3. 562 and 649
4. 476