Clare walks 11,243 steps on Saturday and 12,485 steps on Sunday.

1. How many steps does Clare take altogether on Saturday and Sunday?
2. How many more steps does Clare take on Sunday than on Saturday?

1. Find the value of the sum. Explain your calculations.

   

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2. Find the value of the difference. Explain your calculations.

   

Find the value of each sum and difference using the standard algorithm.

Han finds the value of \(300,\!526 - 4,\!472\).

1. How can you tell by estimating that Han has made an error?
2. What error did Han make?
3. Find the value of \(300,\!526 - 4,\!472\).

In 2018, the population of Boston is estimated as 694,583 and the population of Seattle is estimated as 744,995.

1. Is the population difference between Boston and Seattle more or less than 100,000? Explain how you know.
2. Is the population difference more or less than 50,000? Explain how you know.
3. Find the difference in the populations of the 2 cities.

Han says he uses a method to find the value of \(1,\!000,\!000 - 267,\!923\) without decomposing a unit: “I write 1,000,000 as \(999,\!999 + 1\).”

1. How might rewriting 1,000,000, as Han suggested, help with finding the difference of \(1,\!000,\!000 - 267,\!923\)?

2. Try Han’s method to find \(1,\!000,\!000 - 267,\!923\).

Use the information to determine when the telephone, printing press, and automobile were first invented.

• The airplane was invented in 1903.
• The printing press was invented 453 years before the most recent invention.
• The automobile was invented 15 years before 1900.
• It was 426 years after the invention of the printing press that the telephone was invented.
• The automobile and telephone were invented the closest together in time with only 9 years between them.