Using a calculator 25
(iii) Press 6 and 2.4
6 appears on the screen.
(iv) The cursor now needs to be moved; this is
achieved by using the cursor key (the large
blue circular function in the top centre of the
calculator). Press →
(v) Press −
(vi) Type in 1.9, press x , then press 4.
(vii) Press = and the answer 178.07087... appears.
Thus, 2.4 6 − 1.9 4 = 178.071 correct to 3 decimal
places.
Now try the following Practice Exercise
Practice Exercise 14 Reciprocal and power
functions (answers on page 341)
1. Evaluate
1
1.75
correct to 3 decimal places.
2. Evaluate
1
0.0250
3. Evaluate
1
7.43
correct to 5 significant figures.
4. Evaluate
1
0.00725
correct to 1 decimal place.
5. Evaluate
1
0.065
−
1
2.341
correct to 4 significant figures.
6. Evaluate 2.1
4
7. Evaluate (0.22)
5 correct to 5 significant
figures in engineering form.
8. Evaluate (1.012) 7 correct to 4 decimal
places.
9. Evaluate (0.05) 6 in engineering form.
10. Evaluate 1.1 3 + 2.9 4 − 4.4 2 correct to 4 significant figures.
4.3.3 Root and ×10 x functions
Locate the square root function
√
and the
√
function (which is a Shift function located above
the x function) on your calculator. Also, locate the
×10 x function and then check the following worked
examples.
Problem 11. Evaluate
√
361
(i) Press the
√
function.
(ii) Type in 361 and
√
361 appears on the screen.
(iii) Press = and the answer 19 appears.
Thus,
√
361 = 19.
Problem 12. Evaluate
4
√
81
(i) Press the
√
function.
(ii) Type in 4 and
4
√
appears on the screen.
(iii) Press → to move the cursor and then type in 81
and
4
√
81 appears on the screen.
(iv) Press = and the answer 3 appears.
Thus,
4
√
81 = 3.
Problem 13. Evaluate 6 × 10 5 × 2 × 10 −7
(i) Type in 6
(ii) Press the ×10 x function (note, you do not have
to use ×).
(iii) Type in 5
(iv) Press ×
(v) Type in 2
(vi) Press the ×10 x function.
(vii) Type in −7
(viii) Press = and the answer
3
25
appears.
(ix) Press the S ⇔ D function and the fraction
changes to a decimal: 0.12
Thus, 6 × 10 5 × 2 × 10 −7 = 0.12
Now try the following Practice Exercise
Practice Exercise 15 Root and ×10 x
functions (answers on page 341)
1. Evaluate
√
4.76 correct to 3 decimal places.
2. Evaluate
√
123.7 correct to 5 significant
figures.
(iii) Press 6 and 2.4
6 appears on the screen.
(iv) The cursor now needs to be moved; this is
achieved by using the cursor key (the large
blue circular function in the top centre of the
calculator). Press →
(v) Press −
(vi) Type in 1.9, press x , then press 4.
(vii) Press = and the answer 178.07087... appears.
Thus, 2.4 6 − 1.9 4 = 178.071 correct to 3 decimal
places.
Now try the following Practice Exercise
Practice Exercise 14 Reciprocal and power
functions (answers on page 341)
1. Evaluate
1
1.75
correct to 3 decimal places.
2. Evaluate
1
0.0250
3. Evaluate
1
7.43
correct to 5 significant figures.
4. Evaluate
1
0.00725
correct to 1 decimal place.
5. Evaluate
1
0.065
−
1
2.341
correct to 4 significant figures.
6. Evaluate 2.1
4
7. Evaluate (0.22)
5 correct to 5 significant
figures in engineering form.
8. Evaluate (1.012) 7 correct to 4 decimal
places.
9. Evaluate (0.05) 6 in engineering form.
10. Evaluate 1.1 3 + 2.9 4 − 4.4 2 correct to 4 significant figures.
4.3.3 Root and ×10 x functions
Locate the square root function
√
and the
√
function (which is a Shift function located above
the x function) on your calculator. Also, locate the
×10 x function and then check the following worked
examples.
Problem 11. Evaluate
√
361
(i) Press the
√
function.
(ii) Type in 361 and
√
361 appears on the screen.
(iii) Press = and the answer 19 appears.
Thus,
√
361 = 19.
Problem 12. Evaluate
4
√
81
(i) Press the
√
function.
(ii) Type in 4 and
4
√
appears on the screen.
(iii) Press → to move the cursor and then type in 81
and
4
√
81 appears on the screen.
(iv) Press = and the answer 3 appears.
Thus,
4
√
81 = 3.
Problem 13. Evaluate 6 × 10 5 × 2 × 10 −7
(i) Type in 6
(ii) Press the ×10 x function (note, you do not have
to use ×).
(iii) Type in 5
(iv) Press ×
(v) Type in 2
(vi) Press the ×10 x function.
(vii) Type in −7
(viii) Press = and the answer
3
25
appears.
(ix) Press the S ⇔ D function and the fraction
changes to a decimal: 0.12
Thus, 6 × 10 5 × 2 × 10 −7 = 0.12
Now try the following Practice Exercise
Practice Exercise 15 Root and ×10 x
functions (answers on page 341)
1. Evaluate
√
4.76 correct to 3 decimal places.
2. Evaluate
√
123.7 correct to 5 significant
figures.