Page 63 - TG_G1_CH6_CHRIS

6 - 10 Problem-Solving Strategies
WARM-UP

On Level

Standards
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- INDIVIDUAL
digit number and a multiple of 10, Material: marbles
using concrete models or drawings Instruction: Take 28 marbles and put 10 marbles in one box. Put the rest in the
and strategies based on place value, second box. Ask: How do you find how many marbles are in the second box?
properties of operations, and/or the 28 – 10 = 18
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 Reteach
tens and tens, ones and ones; and
sometimes it is necessary to compose
a ten. Time: 10 minutes
1.NBT.C.5 Given a two-digit number, INDIVIDUAL
mentally find 10 more or 10 less than Material: counters
the number, without having to count; Instruction: Hand out 30 counters to one group and give 20 counters to another
explain the reasoning used. group. Ask: How many counters do they have altogether?
1.NBT.C.6 Subtract multiples of 10 in 20 + 30 = 50
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 Enrich
place value, properties of operations,
and/or the relationship between Time: 10 minutes
addition and subtraction; relate the
strategy to a written method and INDIVIDUAL
explain the reasoning used. Material: counters

Objectives Instruction: Give a child 50 counters. Say: Julia is 10 years old, and her mother is 40
years old. Use the counters to determine how many years older her mother is.
Solve word problems concerning 40 – 10 = 30
2-digits addition and subtraction.

Essential Question
How can you use the problem-solving problem strategy?
Apply the steps of the strategy Read and understand the
problem. Make a plan. Carry out the plan.
Check whether the answer is reasonable or not.
Ready to Go
Say: You have studied numbers up to
100. Today you will use the problem-
solving strategy to solve real- life
problems.
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