Question

multiply or divide

1. \\(\

$$\begin{array}{r} 314 \\\\ \\times\\ 623 \\\\ \\hline \\end{array}$$

\\) 16. \\(\

$$\begin{array}{r} 4.152 \\\\ \\times\\ 351 \\\\ \\hline \\end{array}$$

\\) 17. \\(\

$$\begin{array}{r} 0.83 \\\\ \\times\\ 0.165 \\\\ \\hline \\end{array}$$

\\) 18. \\(\

$$\begin{array}{r} 0.61 \\\\ \\times\\ 0.7 \\\\ \\hline \\end{array}$$

\\)

1. \\(86 \overline{)6.278}\\) 20. \\(27 \overline{)53.570}\\) 21. \\(0.04 \overline{)64}\\) 22. \\(3.8 \overline{)17.48}\\)

Explanation:

Step1: Multiply 314 by 623

Break down 623 as 600+20+3:
$314\times3=942$
$314\times20=6280$
$314\times600=188400$
Sum: $188400+6280+942=195622$

Step2: Multiply 4.152 by 351

Break down 351 as 300+50+1:
$4.152\times1=4.152$
$4.152\times50=207.6$
$4.152\times300=1245.6$
Sum: $1245.6+207.6+4.152=1457.352$

Step3: Multiply 0.83 by 0.165

Count total decimal places: 2+3=5
$83\times165=13695$
Place decimal: $0.13695$

Step4: Multiply 0.61 by 0.7

Count total decimal places: 2+1=3
$61\times7=427$
Place decimal: $0.427$

Step5: Divide 6.278 by 86

Rewrite as $\frac{6.278}{86}=0.073$

Step6: Divide 53.570 by 27

$\frac{53.570}{27}\approx1.984$ (rounded to 3 decimals)

Step7: Divide 64 by 0.04

Rewrite as $\frac{64}{0.04}=\frac{6400}{4}=1600$

Step8: Divide 17.48 by 3.8

Multiply numerator/denominator by 10: $\frac{174.8}{38}=4.6$

Answer:

1. $195622$
2. $1457.352$
3. $0.13695$
4. $0.427$
5. $0.073$
6. $\approx1.984$
7. $1600$
8. $4.6$