Page 51 - TG_G1_CH6_CHRIS

6 - 8 Subtract Tens
WARM-UP

On Level

Standard
1.NBT.C.6. Subtract multiples of 10 in Time: 10 minutes
the range 10-90 from multiples of 10
in the range 10-90 (positive or zero WHOLE CLASS
differences), Using concrete models Material: counters
or drawings and strategies based on Instruction: Draw one box labeled tens and another labeled ones. Give one child
place value, properties of operations 20 counters, Say: put 10 counters in each box, and then take 7 away. Ask: How
and/or the relationship between many counters are left? Say: Write in it the boxes.
addition and subtraction; relate the 20 – 7 = 13
strategy to a written method and
explain the reasoning used.
Objective

Subtract tens using crossing out and a
place value chart.
Reteach
Essential Question
How can I subtract tens? Time: 10 minutes
90 – 50 = _______
Using crossing out method cross out 5 INDIVIDUAL
tens out of 9 tens Material: part-part-whole model 20
The answer is 4 tens = 40. Instruction: Say: Use part – part whole
model to subtract 20 from 50. 50
Ready to Go
Say: In the last lesson, you studied 20 30
two 2-digit numbers with regrouping.
Today you will learn to subtract tens. 50

Enrich

Time: 10 minutes

INDIVIDUAL
Material: dimes
Instruction: Give children 6 dimes. Ask: How many tens do you have? Take away 4
dimes, how many tens do you have?
6 dimes – 4 dimes = 60 – 40 = 20 = 2 dimes

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