Curriculum>Grade 1> Module 2>Topic B: Counting On or Taking from Ten to Solve Result Unknown and Total Unknown Problems
Given a subtraction equation that crosses 10, break down the number being subtracted using a number bond. Break down the original equation and solve for 10, then subtract the remaining amount to find the difference. Both steps are performed mentally
A. Solve subtraction problems taking from 10
B. Subtract single digits from numbers 11-19 to make 10
C. Subtract the digit in the ones place from numbers 11-19 to make 10
D. Find the unknown number in subtraction problems to make 10
E. Solve subtraction problems beginning with a number from 11-15 and crossing 10
F. Use the strategy of making 10 to solve subtraction equations
G. Introduce subtraction across 10 using base-ten blocks
H. Model subtraction across 10 using base-ten blocks and knowledge of number bonds
I. More practice subtracting across 10 with base-ten blocks
J. Use number bonds to break down components of subtraction equations; use two equations to solve
L. Solve subtraction equations by using the strategy of making 10
M. Solve subtraction equations that cross 10