1.1 Introduction to whole numbers  (Page 3/18)

Solution

ⓐ

Locate the hundreds place in 103,978.
Underline the digit to the right of the hundreds place.
Since 7 is greater than or equal to 5, add 1 to the 9. Replace all digits to the right of the hundreds place with zeros.
	So, 104,000 is 103,978 rounded to the nearest hundred.

ⓑ

Locate the thousands place and underline the digit to the right of the thousands place.
Since 9 is greater than or equal to 5, add 1 to the 3. Replace all digits to the right of the hundreds place with zeros.
	So, 104,000 is 103,978 rounded to the nearest thousand.

ⓒ

Locate the ten thousands place and underline the digit to the right of the ten thousands place.	$$
Since 3 is less than 5, we leave the 0 as is, and then replace the digits to the right with zeros.	$$
	$$ So, 100,000 is 103,978 rounded to the nearest ten thousand.

Solution

$\begin{array}{cccccc}\text{Is}\mathrm{5,625}\text{divisible by}2?\hfill & & & & & \\ \text{Does it end in}0,2,4,6,\text{or}8?\hfill & & & & & \text{No.}\hfill \\ & & & & & \mathrm{5,625}\text{is not divisible by}2.\hfill \\ \\ \\ \text{Is}\mathrm{5,625}\text{divisible by}3?\hfill & & & & & \hfill \\ \text{What is the sum of the digits?}\hfill & & & & & 5+6+2+5=18\hfill \\ \text{Is the sum divisible by}3?\hfill & & & & & \text{Yes.}\mathrm{5,625}\text{is divisible by}3.\hfill \\ \\ \\ \text{Is}\mathrm{5,625}\text{divisible by}5\text{or}10?\hfill & & & & & \hfill \\ \text{What is the last digit? It is}5.\hfill & & & & & \mathrm{5,625}\text{is divisible by}5\text{but not by}10.\hfill \\ \\ \\ \text{Is}\mathrm{5,625}\text{divisible by}6?\hfill & & & & & \\ \text{Is it divisible by both}2\text{and}3?\hfill & & & & & \text{No,}\mathrm{5,625}\text{is not divisible by}2,\text{so}\mathrm{5,625}\text{is}\hfill \\ & & & & & \text{not divisible by}6.\hfill \end{array}$