Page 12 - Length

A trundle wheel is a simple device for
measuring distances that are too long for
a tape measure, or that are not always in a
straight line. It consists of a wheel with a
scale around its edge. The wheel is attached
to a long handle. You can push it along the
path that you want to measure. Every time
it completes a full turn, it makes a click.

To use a trundle wheel to measure
distances, you need to know what distance
is covered if the wheel turns around once.

2. If your school has a trundle wheel, A trundle wheel
use it to measure some distances.
First estimate the distance and then
measure it.

3. Which instrument will you use to measure the following
lengths or distances?

(a) the length of the longest wall of your school building
(b) the distance around a soccer field

(c) the length of your pencil

(d) the thickness of a toffee

(e) the height of the door in your classroom

4.6 Rounding off

In mathematics, we often round off An approximation
numbers to numbers that are easy to is close to the exact
work with. Rounding is a way of number, a little more
estimating. Numbers that are rounded or a little less.
off are approximations.

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