Common Core Alignment:.

1.MD.3:

Measurement And Data

Tell And Write Time.

Tell and write time in hours and half-hours using analog and digital clocks.

1.NBT.4:

Number And Operations In Base Ten

Use Place Value Understanding And Properties Of Operations To Add And Subtract.

Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.

2.NBT.5:

Number And Operations In Base Ten

Use Place Value Understanding And Properties Of Operations To Add And Subtract.

Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.

2.NBT.9:

Number And Operations In Base Ten

Use Place Value Understanding And Properties Of Operations To Add And Subtract.

Explain why addition and subtraction strategies work, using place value and the properties of operations.3