### Home > GB8I > Chapter 8 Unit 9 > Lesson INT1: 8.1.3 > Problem8-48

8-48.

Rewrite each expression in scientific notation.

Read the Math Notes boxes in Lesson 1.3.1 on scientific notation and Lesson 1.3.2 on laws of exponents.

1. $1.24 × 10^{3} + 2.3 × 10^{4}$

Convert $1.24×10^{3}$ to $\text{___}×10^{4}$. With common scientific notations you can add the numbers.

1. $\frac { 4 \times 10 ^ { 5 } } { 8 \times 10 ^ { 7 } }$

Write $\frac{4}{8}$ as a decimal $(0.5)$.

Simplify $(\frac{10^5}{10^7})$ using laws of exponents.

So $0.5×10^{-2}$ results. Now rewrite in standard form and convert back to scientific notation.

1. $8.5 × 10^{10} · 7.6 × 10^{12}$

Use the Commutative Property of Multiplication to reorder the terms, so multiply $(8.5 · 7.6)(10^{10}· 10^{12})$.