3. สัญกรณ์วิทยาศาสตร์ในแต่ละข้อต่อไปนี้แทนจำนวนใด
1) 5 x \(\mathtt{10^{-4}}\)
วิธีทำ
5 x \(\mathtt{10^{-4}}\)
= 5 x \(\mathtt{\frac{1}{10^4}}\)
= 5 x \(\mathtt{\frac{1}{10,000}}\)
= 5 x 0.0001
= 0.0005
= 5 x 0.0001
= 0.0005
ตอบ 0.0005
2) 9 x \(\mathtt{10^{-6}}\)
วิธีทำ
9 x \(\mathtt{10^{-6}}\)
= 9 x \(\mathtt{\frac{1}{10^6}}\)
= 9 x \(\mathtt{\frac{1}{1,000,000}}\)
= 9 x 0.000001
= 0.000009
= 9 x 0.000001
= 0.000009
ตอบ 0.000009
3) 1.2 x \(\mathtt{10^{-5}}\)
วิธีทำ
1.2 x \(\mathtt{10^{-5}}\)
= 1.2 x \(\mathtt{\frac{1}{10^5}}\)
= 1.2 x \(\mathtt{\frac{1}{100,000}}\)
= 1.2 x 0.00001
= 0.000012
= 1.2 x 0.00001
= 0.000012
ตอบ 0.000012
4) 6.82 x \(\mathtt{10^{-7}}\)
วิธีทำ
6.82 x \(\mathtt{10^{-7}}\)
= 6.82 x \(\mathtt{\frac{1}{10^7}}\)
= 6.82 x \(\mathtt{\frac{1}{10,000,000}}\)
= 6.82 x 0.0000001
= 0.000000682
= 6.82 x 0.0000001
= 0.000000682
ตอบ 0.000000682
5) 5.4013 x \(\mathtt{10^{-8}}\)
วิธีทำ
5.4013 x \(\mathtt{10^{-8}}\)
= 5.4013 x \(\mathtt{\frac{1}{10^8}}\)
= 5.4013 x \(\mathtt{\frac{1}{100,000,000}}\)
= 5.4013 x 0.00000001
= 0.000000054013
= 5.4013 x 0.00000001
= 0.000000054013
ตอบ 0.000000054013
6) 8.9 x \(\mathtt{10^{-9}}\)
วิธีทำ
8.9 x \(\mathtt{10^{-9}}\)
= 8.9 x \(\mathtt{\frac{1}{10^9}}\)
= 8.9 x \(\mathtt{\frac{1}{1,000,000,000}}\)
= 8.9 x 0.000000001
= 0.0000000089
= 8.9 x 0.000000001
= 0.0000000089
ตอบ 0.0000000089