Speed Counting. Addition and Subtraction

How to learn to calculate in your mind and without mistakes? It is so frustrating when teachers reduce grades for inattention. Speed counting exercises will help your child practice addition and subtraction skills. Just 16 days of regular practice for 10-15 minutes, and you will notice the first results and good grades in the report card.
-we study using an effective method
-we calculate quickly without a calculator
-we solve without mistakes