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6 - 6 Adding a Two-Digit Number and a Multiple of 10
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: abacus
Instruction: Use an abacus to add 36 + 20 = ____.
using concrete models or drawings
and strategies based on place value,
properties of operations, and/or the
relationship between addition and Tens Ones Tens Ones Tens Ones
subtraction; relate the strategy to
a written method and explain the 36 + 20 = 56
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
Objectives

Add 2-Digit number and a multiple of Time: 10 minutes
ten using the place value chart and INDIVIDUAL
models. Material: number cards (numbered 1 to 100)
Instruction: Divide the class into four groups. Give one group number cards
Essential Question 1 to 25, the second group number cards 26 to 50, the third group number cards 51

How can I add two-digit numbers to 75, and the fourth group number cards from 76 to 100. Have each group pick out
the number cards that show multiples of ten and place them on the table.
with tens? Add the tens with the tens 10, 20
and the ones with the ones. 30, 40, 50
Ex: 35 + 40 =______ 60, 70
3 tens ,5 ones and 4 tens = 7 tens ,5 80, 90, 100
ones = 75

Ready to Go
Say: Last lesson was about add tens Enrich
and ones, today you will study adding
two 2-digit numbers.
Time: 10 minutes

INDIVIDUAL
Material: dimes and pennies
Instruction: Ask: a student to show you 26 using dimes and pennies. How many tens
and ones are in 26? Add 2 dimes. How many tens and ones now?

26 = 2 dimes and 6 pennies. When adding 2 other dimes, I have 4 dimes and 6
pennies. 26 + 20 = 46.
430