Khan Academy

Subtracting 1, 10, or 100 (K-A)

Subtracting 1s, 10s, and 100s-video (K-A)

Subtracting 3-digit numbers (no regrouping) (K-A)

Adding and subtracting on number line-video (K-A)

Addition using groups of 10 and 100-video (K-A)

Breaking apart 3-digit addition problems- video (K-A)

Solving 3-digit addition in your head-video (K-A)

Adding 10 or 100 (K-A)

Adding 1s, 10s, and 100s (K-A)

Adding and subtracting on number line (K-A)

Adding four two digit numbers (K-A)

Adding multiple 2-digit numbers word problems (K-A)

Adding 3-digit numbers (no regrouping) (K-A)

Addition using groups of 10 and 100 (K-A)

Breaking apart 3-digit addition problems (K-A)

Adding and subtracting on number line (K-A)

Subtracting 1, 10, or 100 (K-A)

Subtracting 1s, 10s, and 100s (K-A)

Subtracting 3-digit numbers (no regrouping) (K-A)

Subtracting with place value blocks (regrouping) (K-A)

Measuring lengths 2 (K-A)

Measuring lengths with different units (K-A)

Measuring lengths with different units-video (K-A)

Comparing lengths (K-A)

Comparing lengths-video (K-A)