Theme 6.  Adding a round number to a two-digit number (45 + 20). Subtracting a round number from a two-digit number (45 – 20)

In the theme you learn:
• you will learn how to add and subtract round numbers up to 100;
• you will find out how many tens and ones are in a two-digit number;
• you will improve your skills in adding and subtracting numbers up to 100;
• you will solve problems to find the unknown minuend, to increase and decrease a number by a few units;
• you will practice comparing named numbers written in kilograms.