Mathematics for Carpenters and Builders - Carpenter's and Builder's Math, Plans, and Specifications - page 116

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The sign of multiplication is , and it is read “times” or “mul-

tiplied by.” The numbers may be taken in any order when
multiplying (4

× 7 is the same as 7 × 4).

The sign of division is , and it is read “divided by.” A series

of divisions must be taken in the order written (100

÷

÷ 2) ÷

10 = 5.

The sign of equality is , and it is read “equals” or “is equal

to.” The expressions on each side of an equality sign must be
numerically the same. The complete expression is called an
equation .

=

Use of the Signs of Operation
Following are some examples of the use of mathematical signs of
operation.
Example Use of the sign of addition . A builder when building a
house buys 1762 board feet of lumber from one yard, 2176 board
feet from another, and 276 board feet from another. How many
board feet did he buy?
The problem:
1762

+ 2176 + 276 = ?

The solution:
1762
2176
+

276
4214 board feet

Note how the numbers are aligned to permit addition. The units are
all aligned on the right, then the tens, then the hundreds, then the
thousands, each in the proper column.
Example Use of the sign of subtraction . A carpenter bought 300
pounds of nails for a job, and he had 28 pounds left when he finished.
How many pounds of nails did he use to complete the job?
The problem:
300

− 28 = ?

The solution:
300
−

28
272 pounds

Note that the numbers must be aligned as they were for addition.