Question bank: Rounding

In a construction project, the engineer needs to determine the amount of paint needed to paint a large wall. He measured the area to be painted and obtained the value of 397.25 square meters. However, when consulting the paint manufacturer's catalog, he realized that paint cans are sold in pre-established volumes: 1 liter, 2.5 liters, and 5 liters. To optimize the cost of the project, the engineer wants to buy the smallest amount of cans possible, without failing to cover the entire wall. Considering that each paint can covers exactly the amount indicated on the label and that the paint yield is the same on any surface, determine the smallest number of 2.5-liter paint cans the engineer should buy and justify rounding to the nearest unit. Also, explain why there can be no waste when rounding the number of cans up or down.

During a Science class, the 6th-grade students went out for a weather observation. They recorded the air temperature in various locations of the school using digital thermometers. While noting the readings, they noticed that the records had a precision of tenths of degrees Celsius. To facilitate the communication of the observed temperatures, they decided to round the values to the nearest temperature that could be expressed in whole degrees Celsius. If the thermometer readings at a certain moment were 23.6°C; 24.4°C; 25.0°C; 25.9°C; and 26.2°C, what temperature did each reading represent after rounding to the nearest whole degree?

The planning of a school garden involves the proper spacing between plants to ensure their healthy growth. A group of 6th-grade students decides to plant 64 carrots in a straight line, leaving an exact space of 10 centimeters between each plant. However, they realize that the total length of the carrot line is not an exact multiple of one meter, the standard measurement they use to make markings in the garden. To solve this practical issue, the group decides to round the total measurement to the nearest meter in order to correctly plan the amount of material needed for the markings. Considering only the total length of the carrot line and the fixed spacing of 10 centimeters between them, what rounding technique should the students use and what could be the impact of incorrect rounding on the distribution of plants in the garden?

What is the number closest to 579 when rounded to the nearest hundred?

In a science project, students need to measure different volumes of liquids for their experiments. The scale used to measure the volume of water can only measure in multiples of 100 milliliters. When measuring, the scale shows 450.725 grams of water. We know that the density of water is 1 g/ml. (1) Round the volume measured by the scale to the nearest milliliter. (2) Explain why the scale provided a number in grams instead of milliliters and how you used the density of water to convert the measurement back to volume in milliliters.