First-year students can add or subtract within 100 in 100 courses. Pass in 25 minutes and get good grades in 20 minutes.

If it is 30 tracks, 3 -5 minutes is recommended. The operation of finding the other addend by knowing two addends and one of them. You can let your child remember 6 in his mind, then stretch out four fingers and count from 6 to the back. Let the children do the calculation, that is, make up 10.