Free printable math drill — download and print instantly
This Subtraction Within 20 drill has 40 problems for Grade 1. Music theme. Answer key included.
⬇ Download Free Math DrillGet new free worksheets every week.
All worksheets checked by our AI verification system. No wrong answers — guaranteed.
Max's favorite band's instruments disappeared! He must solve subtraction problems to unlock each musical note before the concert starts tonight!
Standard: CCSS.MATH.1.OA.C.6
Subtraction-within-20 is a cornerstone skill that helps six- and seven-year-olds move beyond counting on their fingers and develop true number sense. At this age, children are building the mental flexibility to recognize that 15 – 3 can be solved by counting backward or by knowing that 3 and 12 make 15. This skill directly supports their ability to solve real-world problems—like figuring out how many crayons are left after sharing some with a friend, or determining change at a store. Fluency with subtraction-within-20 also strengthens their confidence in math and prepares them for two-digit subtraction and addition in Grade 2. When children practice these problems repeatedly, they're not just memorizing facts; they're building neural pathways that make math feel less intimidating and more intuitive. Strong foundational subtraction skills reduce anxiety and foster a positive relationship with numbers that lasts throughout their education.
Many Grade 1 students confuse the direction of subtraction and count up instead of counting back—for example, solving 12 – 5 by counting 5 up from 12 rather than 5 back from 12, which leads to the wrong answer. You'll spot this when a child says 12 – 5 = 17 or seems to be adding instead of subtracting. Another frequent error is forgetting to track which number you're subtracting from; students might solve 15 – 7 but accidentally compute 7 – 15. Watch for answers that are too large (larger than the first number) or when a child seems to lose track partway through counting backward. Encourage them to touch or point to each count to maintain accuracy.
Play a simple game with snacks or small objects at home: place 12 crackers or blocks in front of your child, announce 'we're eating 4,' and have them physically remove that amount while saying the numbers backward aloud ('12, 11, 10, 9'). This multi-sensory approach—moving, speaking, and seeing—helps six-year-olds anchor the subtraction concept. Rotate who chooses the starting number and what gets subtracted so your child stays engaged and builds flexibility with different facts.