Houghton Mifflin Harcourt
Mental Math: Subtract Tens - Homework 12.1
Now that your class can add by 10s they can start subtracting by 10s. This clear, learner-friendly learning exercise provides a good example (10-rods are pictured) and 7 problems to solve. Relates groups of tens to single-digit numbers,...
Mangahigh
Mangahigh: Number: Add and Subtract Tens and Hundreds
Determine the sum and difference when adding and subtracting tens and hundreds.