Theme 8.  Column addition and subtraction of two-digit numbers (45 + 22, 45 – 22)

In the theme you learn:
• You will find the number of tens and ones in two-digit numbers up to 100;
• You will learn about column addition and subtraction of two-digit numbers;
• You will practice comparing named numbers written in kilograms;
• You will improve your skills in adding and subtracting numbers up to 100;
• You will solve problems to find the sum, compare numbers by difference, and increase a number by a few units;
• You will practice changing named numbers written in centimeters and decimeters.