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6 - 7 Adding 2-Digit Numbers with Regrouping
WARM-UP

On Level

Standard
1.NBT.C.4. Add within 100, including Time: 10 minutes
adding a two-digit number and a
one-digit number, and adding a two- WHOLE CLASS
digit number and a multiple of 10, Material: Boxes and pens
Instruction: Give a child 4 boxes and write on each only 10 pens. Hand out 26
using concrete models or drawings pens and ask children to put them in the boxes. Ask: How many complete boxes do
and strategies based on place value, we have now? Hand out an extra 8 pens. Ask: How many complete boxes now?
properties of operations, and/or the And how many pens left?
relationship between addition and 10 + 10 = 20 26 = 20 + 6
subtraction; relate the strategy to 2 full boxes and 6 more pens
a written method and explain the 10 + 10 + 10 = 30 26 + 8 = 34 = 30 + 4
3 full boxes and 4 more pens
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. Reteach
Objective

Add a two-digit number and a one- Time: 10 minutes
digit number by composing a ten. INDIVIDUAL
Material: Cubes
Essential Question Instruction: Give each group of students 29 cubes and then 5 cubes. Ask: What is

How can I add two-digit numbers with the sum so that each 10 cubes make a tower of 10?
29 + 5 = 34
one digit numbers with regrouping? 3 towers of 10 and 4 ones
56 + 8 = _______
When adding ones, if the total is more
than 10, regroup into a 10 and some
ones, then move the ten from the Enrich
ones place to the tens place.

e.g. 56 + 8 = 50 + 6 + 8 Time: 10 minutes
6 + 8 = 14 INDIVIDUAL
50 + 10 + 4 = 64
Material: place value chart Tens Ones
Ready to Go Instruction: Use the place value chart and write the

Say: In the last lessonn you studied number 30 four different ways as tens and ones.
adding two 2-digit numbers. Today
you will study two 2-digit numbers with
regrouping. Tens Ones Tens Ones Tens Ones Tens Ones
3 0 2 10 1 20 0 30

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