Answer:
a) Error: Moving the decimal point without changing the exponent changes the value of the number. The final number reported is different from the one computed.
b) Correct work: (see below)
... Correct solution: 1.035×10¹¹
Step-by-step explanation:
a) When the decimal point is moved to the left in the mantissa, its value is divided by 10 for each place the decimal point is moved. To keep the overall value of the number the same, the power of 10 must be increased to compensate. The increase in the exponent is the number of places the decimal point is moved left.
In this problem, the decimal point is moved 1 place left, so the exponent needs to be increased from 10 to 11.
b) Correct work:
[tex]\displaystyle(7.14\cdot 10^{10})+(3.21\cdot 10^{10})=(7.14+3.21)\cdot 10^{10}\\\\=10.35\cdot 10^{10}=1.035\cdot 10^{11}[/tex]
