Calculations in Run-Matrix

3.1Order of operations and negatives#

Powers and roots come first, then multiplication and division, then addition and subtraction. Brackets change the order. Use (−) for the sign of a number and − for subtraction.

Example 3.1

A negative number

1. Type -5 + 2.

   (−)5+2EXE

3.2Add and multiply fractions#

Press / for a fraction template: type the numerator, press ▼ for the denominator, then ▶ to step out. A number typed before / becomes the numerator.

Example 3.2

Add two fractions

$$\frac13+\frac16=\frac12$$

1. Type 1/3 + 1/6.

   /1▼3▶+/1▼6EXE

Example 3.3

Number first

1. Type 2/3 × 3/4 by typing the numbers first.

   2/3▶×3/4EXE

Example 3.4

A decimal as a fraction

1. 0.1 + 0.2 comes out exact.

   0.1+0.2EXE

3.3Mixed numbers#

SHIFT// opens a mixed-number template (whole part, numerator, denominator). SHIFTab/c⇔d/cS⇔D switches an answer between mixed and improper form.

Example 3.5

Add to a mixed number

1. Type 1 1/2 + 1/2.

   SHIFT//1▶1▶2▶+1/2EXE

Example 3.6

Show 7/2 as a mixed number

1. Calculate 7/2, then SHIFT S⇔D.

   7/2EXESHIFTab/c⇔d/cS⇔D

3.4Exact answers and decimals#

Answers stay exact when they can: 1/3, 2√2, π. Press S⇔D to switch the last answer to a decimal and back.

Example 3.7

Fraction to decimal

1. 1/3, then S⇔D.

   1/3EXES⇔D

Example 3.8

Back to exact

1. S⇔D again.

   1/3EXES⇔DS⇔D

Example 3.9

Root to decimal

1. Square root of 2 times 2, then S⇔D.

   2SHIFT√x²2EXES⇔D

3.5Roots and π#

Roots are simplified. Multiples of π are exact.

Example 3.10

Simplify a root

1. SHIFT x² then 8.

   SHIFT√x²8EXE

Example 3.11

Rationalize

1. 1 divided by √2.

   1/SHIFT√x²2EXE

Example 3.12

Multiples of π

1. 2 times π.

   2SHIFTπ×10ˣEXE

3.6Powers, roots and logarithms#

Example 3.13

A power

1. 2 to the power 10.

   2^10EXE

Example 3.14

Step out of an exponent

1. 2³ + 1, pressing right after the 3.

   2^3▶+1EXE

Example 3.15

A cube root

1. The cube root of 27.

   SHIFT∛(27EXE

Example 3.16

A fourth root

1. Index 4, then 81.

   SHIFTˣ√^4▶81EXE

Example 3.17

Reciprocal

1. 4, then SHIFT ).

   4SHIFTx⁻¹)EXE

Example 3.18

Log base 10

1. log 100.

   log100EXE

Example 3.19

Natural log

1. ln of e cubed.

   lnSHIFTeˣln3EXE

3.7Scientific notation#

Press ×10ˣ to type "times ten to the power". Very large answers are shown as ×10 to a power.

Example 3.20

2 × 10³

1. Type 2, ×10ˣ, 3.

   2×10ˣ3EXE

Example 3.21

A negative exponent

1. 2 ×10 to the minus 3.

   2×10ˣ(−)3EXE

Example 3.22

A very large answer

1. 999999 to the fourth power, using two squarings.

   999999x²x²EXE

3.8Ans, history and recall#

The last answer is stored as Ans. Press SHIFTAns(−) to type it, or start a line with an operator. The calculator keeps your last 30 entries; use ▲ and ▼ to recall them.

Example 3.23

Ans key

1. Calculate 5, then Ans + 1.

   5EXESHIFTAns(−)+1EXE

Example 3.24

History is on screen

1. Do 2 + 3 then 4 × 5.

   2+3EXE4×5EXE