The length of the desk was measured with a ruler. It is equal to 1.3 m. Write down the length of the desk in cm, taking into account the error.

According to the condition, it is given that a centimeter ruler was used: “using a ruler (cm)”. This means that the minimum value measured by this ruler is 1 centimeter. Therefore, we will translate the measured value into centimeters: 1.3 m = (1.3 * 100) cm = 130 cm. The length of 130 cm could be measured absolutely accurately, or it could be rounded. When measuring with a centimeter ruler, you can round to the nearest 0.5 cm, both in the larger and in the smaller directions. This means that, taking into account the rounding error, the length of the school desk is 130 ± 0.5 cm.