diff --git a/part10-multicore/README.md b/part10-multicore/README.md
index 35091a2..4434704 100644
--- a/part10-multicore/README.md
+++ b/part10-multicore/README.md
@@ -80,7 +80,7 @@ Previously, we've unequivocally halted the other cores by spinning them in an in
     cbz     x4, 1b               // Loop if zero, otherwise continue
 
     ldr     x2, =__stack_start   // Get ourselves a fresh stack - location depends on CPU core asking
-    lsl     x1, x1, #9           // Multiple core_number by 512
+    lsl     x1, x1, #9           // Multiply core_number by 512
     add     x3, x2, x1           // Add to the address
     mov     sp, x3
 
diff --git a/part10-multicore/boot.S b/part10-multicore/boot.S
index ef2f5c2..b68fcd6 100644
--- a/part10-multicore/boot.S
+++ b/part10-multicore/boot.S
@@ -29,7 +29,7 @@ _start:
     cbz     x4, 1b
 
     ldr     x2, =__stack_start   // Get ourselves a fresh stack - location depends on CPU core asking
-    lsl     x1, x1, #9           // Multiple core_number by 512
+    lsl     x1, x1, #9           // Multiply core_number by 512
     add     x3, x2, x1           // Add to the address
     mov     sp, x3