Mental Math
Use Mental Math to solve
222+100=
322
Use base ten
500+100
600
Use standard algorithm to solve
200+100
300
Use expanded form
400+200
600
Use mental math to solve
800+100
900
Use mental math to solve
900+100
1,000
Use base ten to solve
199+299
498
Use the standard algorithm
123+456
579
Use expanded form
212+117
329
Use base ten to solve
267+291
558
Use mental math
420+100
520
Use base ten
512+622
1,134
Use standard algorithm
197+862
1,059
Use expanded form
777+999
1,776
Use standard algorithm
412+488
900