Mental Math - 2 Digit Numbers (Addition & Subtraction)

by Smart a la Carte

Price: 200 points or $2 USD

Subjects: math

Grades: 13,1,2,3,4

Description: This deck is designed to help your students quickly master mental math addition and subtraction! Students will look at the 2-digit number and add/subtract either 1 or 10 to/from the number. There are a few tricky ones here, where students must go on/back to the next place (EX. 39 + 1 = 40). The first slide is an instruction slide, which is read aloud automatically. The rest of the slides are numerals only. Perfect for all student levels! CCSS.MATH.CONTENT.1.NBT.C.4 Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the 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 tens and tens, ones and ones; and sometimes it is necessary to compose a ten. CCSS.MATH.CONTENT.1.NBT.C.5 Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used. CCSS.MATH.CONTENT.1.NBT.C.6 Subtract multiples of 10 in 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 place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.