1.NBT. Grade 1 - Number and Operations in Base Ten

1.NBT.A. Extend the counting sequence.

• Counting Circles II

1.NBT.A.1. Count to 120, starting at any number less than 120. In this range, read and write numerals and represent a number of objects with a written numeral.

• Choral Counting II
• “Crossing the Decade” Concentration
• Hundred Chart Digit Game
• Number of the Day
• Start/Stop Counting II
• Where Do I Go?

1.NBT.B. Understand place value.

1.NBT.B.2. Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:

• Roll & Build
• The Very Hungry Caterpillar

1.NBT.B.2.a. 10 can be thought of as a bundle of ten ones–-called a “ten.”

• No tasks yet illustrate this standard.

1.NBT.B.2.b. The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.

• No tasks yet illustrate this standard.

1.NBT.B.2.c. The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).

• No tasks yet illustrate this standard.

1.NBT.B.3. Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols $>$, $=$, and $<$.

• Comparing Numbers
• Ordering Numbers
• Where Do I Go?

1.NBT.C. Use place value understanding and properties of operations to add and subtract.

1.NBT.C.4. 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.

• Ford and Logan Add 45+36

1.NBT.C.5. Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

• Number Square

1.NBT.C.6. Subtract multiples of 10 in the range 10–90 from multiples of 10 in the range 10–90 (positive or zero differences), 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.

• No tasks yet illustrate this standard.