2 ObjectivesSubtract from 200 and from numbers with zeros in the tens place.
3 Fluency: Subtraction from Tens I say a basic fact, you add ten to the whole and continue until I say to stop. So after 10-8=2 you would solve 20-8, and then…?30-8, 40-8, 50-8Yes! As high as you can before I give the signal to stop. Let’s beginReady?10-8=220-8=1230-8=2240-8=3250-8=4260-8=52I put the a few examples of the pattern. Make sure you gauge your class to see where they need to stop.
4 Sprint: Subtraction from a Ten or a Hundred Put your name and number at the top of the page Sprint AOn your mark, get set, THINKLets check your workWrite the number you got correct up topSprint BWhat was your improvement?
5 Application ProblemMr. Ramos has 139 pencils and 88 erasers. How many pencils than erasers does he have?Let your students choose any strategy to solve. Invite pairs of students to share different strategies on the board (ipad)
6 2 steps: 100 100 1 step: 100 Concept Development 0 10 0 9 10 9 10 0 10 0 102 steps: 100Show me 100 with the fewest disks possible.What is the value of your disk?100Change 1 hundred for 10 tens. (don’t for get to draw them in 5-groups)Say the number in hundreds1 hundredNow say the number in tens.10 tens.Did the value change?No!Show me 100 by changing 1 ten for 10 ones.Say the number in hundreds.0 101001 step: 100Have students work on white boards to do drawings. Make sure to give students enough time to draw their pictures before revealing the drawings.1 hundredSay the number in tens and ones9 tens and 10 onesDid the value change?No! It’s still a hundred!Let’s look at it in a written form
7 2 steps: 200 200 1 step: 200 Concept Development 1 10 1 9 10 9 10 1 10 Show me 200 with the fewest disks possibleChange 1 hundred for 10 tensSay the number in hundreds2 hundredSay the number in hundreds and tens1 hundred, 10tensDid the value change?No!Now show me 200 by unbundling a ten.Say the number in hundreds, tens and ones.1 102 steps: 2001 102001 step: 200Have students work on white boards to do drawings. Make sure to give students enough time to draw their pictures before revealing the drawings.
8 Concept DevelopmentWe are going to do the unbundling method of hundreds to tens to ones to help us subtract.Let’s practice with these problems100-83200-8200-78Now it is your turn to practice. Try you very best to complete the problem set.Walk around the classroom and observe student discussion. If needed you can guide them through these problem. You can use your whiteboard or you can use your ipad for this