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🔟 Subtracting Multiples of 10

Practice subtracting tens from tens — like 70 − 30 — using place value, so big-looking problems become as easy as 7 − 3.

lessons

~15 min

to learn

🔢 Math

subject

Ages 6–12

level

Start the course →

What you’ll learn

Tens Are Easy Take-AwaysSubtract multiples of 10 from multiples of 10 using place value, like 70 - 30 = 40.Numbers made of whole tens can be subtracted by counting in tens. 70 is 7 tens and 30 is 3 tens, so 70 - 30 leaves 4 tens, which is 40. On a number line you can jump back one ten at a time to reach the answer.
Show It With BlocksModel subtraction of tens with base-ten blocks and use a known fact plus a zero.Base-ten rods show tens being removed: 90 - 40 leaves five rods, which is 50. The shortcut is to subtract the tens digits using a fact you know and add a zero, so 60 - 20 becomes 6 - 2 = 4, then 40.

Questions this course answers

70 - 30 = ?

7 tens take away 3 tens leaves 4 tens, which is 40.

80 - 50 = ?

Jump back five tens from 80: 70, 60, 50, 40, 30.

Which small fact helps you solve 70 - 30?

70 - 30 works just like 7 - 3, only in tens.

90 - 40 = ?

9 tens take away 4 tens leaves 5 tens, which is 50.

Grounded in trusted sources

Khan Academy Kids
PBS Kids — early math
National Council of Teachers of Mathematics (NCTM)

Every Wunder lesson is built from real, reputable sources — never invented.

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