Choose the most efficient strategy
2nd Grade Math practice: What is an efficient way to solve 398 + 205. Part of extension: mastery (Extension: Mastery).
~10 min
Some problems are easier with mental math, some with place value, and some with a written method.
Tens and ones
47
4 tens
7 ones
A 2-digit number has tens and ones. The tens digit tells how many groups of 10, and the ones digit tells how many extra ones.
💡 Say it like: 47 is 4 tens and 7 ones.