Question

One milliliter of blood contains approximately 5 million red blood cells, and one pint is about 473 milliliters. Create and solve an equation that can be used to find approximately how many red blood cells are in a pint of blood. Use scientific notation for the first box of the equation.

+
5 × 109
2.4 × 109
473
×
5 × 106
9.73 × 109
4.73
–
÷
9.73 × 106
2.4 × 106

Answer 1

Hi catwomen12 --- don't know if you've got this one done yet.
You might consider unit analysis: there's 1 ml blood per 5x10^6 red blood cells;
view this as the fraction
\[ \frac{1\text{ml blood}}{5\times 10^6 \text{ml red blood cells}}\]
Then, since 1 pt = 473 ml, the fraction
\[\frac{1 \text{pt}}{473 \text{ ml blood}}\] is just the number 1!! (Numerator and denominator are the same.)
If you multiply these two fractions together, you're really just *re-naming" the first fraction (since you're multiplying it by one); what cancels out? What's left?