First Yard | Length Calculation
01 1 m is 100 cm
02 1 cm is 10 mm, 1 km is 1000 m
03 Calculate with units of the same length
04 Calculate crosswise using the same length units.
05 10 mm is rounded up to 1 cm, 1000 m is rounded up to 1 km.
06 1 cm is 10 mm, 1 km is 1000 m.

Second Yard | Time Calculation
Read the time in the order of 07 hours, minutes, and seconds.
08 1 hour is 60 minutes, 1 hour 30 minutes is 90 minutes
09 1 minute is 60 seconds, 1 minute 40 seconds is 100 seconds
Add up the hours, minutes, and seconds
11 Add the same time units for horizontal calculations.
12 60 seconds is rounded up to 1 minute
13 60 minutes is rounded up to 1 hour.
14 60 seconds is rounded up to 1 minute, and 60 minutes is rounded up to 1 hour.
Subtract 15 hours, minutes, and seconds
16. Subtract the same time units when calculating horizontally.
17 1 minute is rounded down to 60 seconds
18 1 hour is rounded down to 60 minutes.
19 1 minute is 60 seconds, 1 hour is 60 minutes.

Third Yard | Calculating the Load and Weight
20 1 L is 1000 mL
21 Same units are calculated together
22 1000 mL is rounded up to 1 L
23 1 L is rounded down to 1000 mL
24 1 kg is 1000 g, 1 t is 1000 kg
25 Calculate with the same weight units
26 1000 g is rounded up to 1 kg
27 1 kg is rounded down to 1000 g

Quick Length and Time Calculations for Busy Elementary School Students
Calculating length and time, which elementary school students find difficult, all in one book!

■ Many children have difficulty converting units and calculating.
One of the areas that children struggle with in second and third grade math is unit conversion and calculations.
Students begin to get confused when the units of length learned in the second grade increase to multiple units starting in the third grade.
In particular, many children have difficulty with calculations involving carrying and borrowing in the 'length and time' unit learned in the third grade.
That's why mothers also call it the magic section of elementary math, the black hole.
The relationships between various units can be confusing and lead to many calculation errors if you are not familiar with them, so you need to first solidify the concepts and practice sufficiently.

■ Let's practice by gathering all the length, time, volume, and weight calculations that you learn scattered around!
Among the measurement areas, length calculation, time calculation, and weight calculation are taught in the second semester of the second grade, the first semester of the third grade, and the second semester of the third grade.
This book is organized into one volume, starting from 'length and time' to 'capacity and weight', in a sequence closely related to daily life, just like a textbook.
We've reduced the easy parts of unit calculations and increased the parts that children often make mistakes on and have difficulty with, flexibly arranging the problems.
Therefore, by studying with this book, you can complete all the unit calculations learned in the second and third grades in one book.


■ Let’s practice ‘unit calculation’ step by step, starting from the basics!
This book covers everything from the relationships between different units to unit calculations involving carry-over and carry-back.
In particular, in the 'Time Calculation' section, you can focus on practicing time calculations, including the sum of times with two carry-overs and the difference of times with two carry-overs.

If you are a friend who has completed the second year of school, this book will help you accurately build a foundation in the basics of unit calculations that you will learn in the third year.

■ Learn concepts easily with pictures and fill-in-the-blanks!
This book is structured so that you can understand the concepts on your own by first showing them in pictures and then filling in the blanks.
By looking at a Java map, you can learn the relationship between units of length, and when converting hours to minutes, show them a clock first and explain why there are 60 minutes in an hour rather than calculating mechanically.
It also shows the principle of addition and subtraction through beakers and weights, as well as the principle of difference.
Because you need to know the principles of the measurement area to understand it accurately.


■ After solidifying the concept with training problems, we will challenge ourselves with everyday life sentence problems and play types!
Now that you understand the concept, you should practice with an appropriate amount of problems.
This book is structured so that you practice less of the easy stuff and more of the difficult stuff.
You can also finish each concept with the "Challenge! Sentence Problems" section, which naturally leads to basic sentence problems after learning each concept, and the "Operation Playground" corner, where you can solve problems like a game.
Calculate length, time, volume, and weight easily and enjoyably with 'Busy Length and Time Calculation'!

■ You can start studying in a fun way, starting from the origin of the unit!
This book first introduces the history of the unit for fun before studying it in earnest.
The 'cubit' used in ancient Egypt, known as the oldest unit, and the 'yard', 'inch', and 'foot' used in England are introduced with interesting pictures and text.
Children can begin to learn about the 'meter (m),' a unit of length commonly used around the world.

■ This book's progress chart! Have fun achieving your learning goals with "Padok in the Land of Strange Length and Time"!
The opening pages of this book are designed to help you escape the 'land of strange lengths and times' with Padok while coloring the steps you studied today.
After you finish this book, which consists of three chapters, you can enjoy dinner with your friend, Ppuniy.
Children will be able to let their imagination run wild as if they were Alice in Wonderland, and feel a greater sense of accomplishment when they finish a book.