| The number of cells
in the human body has been estimated to be in the trillions! It would take about 35,000 red blood cells to fill an area of 0.035 cm2. That’s about half the space inside a printed zero on this page. |
|
| You can think of one
trillion as one thousand billion, or one million million. In standard form, one trillion is written as 1,000,000,000,000. |
| Write each underlined number in standard form. | |
| It has been estimated
that the number of cells in a person’s body is between 10 trillion and 100 trillion. |
|
| The human brain
has been estimated to contain more than 100 billion nerve cells. |
|
| It has been
estimated that the amount of heat produced by your muscle cells each day could boil almost 943 milliliters, or 943 thousandths of a liter, of water for an hour. |
|
| The part of
the brain called the gray matter is a layer about two and five tenths millimeters thick. |
|
| A cell is mostly
water. About 70
hundredths of the material in a typical cell is water. |
|
| There are about 250
million red blood cells
in a single drop of blood. |
| Copy the place-value
chart on page 52. Write the underlined numbers from the questions above in the chart. Find more data about human cells and write those numbers in the chart also. |